Political polarization has ushered in a new era in state government, where single-party control of the levers of power has produced competing Americas. One is grounded in principles of lean and limited government and on traditional values; the other is built on a belief in the essential role of government and on tenets of cultural liberalism.

These opposing visions have been a staple of national elections, and in a divided Washington, this polarization has resulted in gridlock and dysfunction. But today, three-quarters of the states — more than at any time in recent memory — are controlled by either Republicans or Democrats. Elected officials in these states are moving unencumbered to enact their party’s agenda.

Republican states have pursued economic and fiscal strategies built around lower taxes, deeper spending cuts and less regulation. They have declined to set up state health-insurance exchanges to implement President Obama’s Affordable Care Act. They have clashed with labor unions. On social issues, they have moved to restrict abortion rights or to enact voter-identification laws, in the name of ballot integrity, that critics say hamper access to voting for the poor and minorities.

Blue states have also been forced to cut spending, given the budgetary pressures caused by the recession. But rather than cutting more deeply, a number of them also have raised taxes to pay for education or infrastructure. They have backed the president on the main elements of his health-care law. The social-issue agenda in blue states includes legalizing same-sex marriages, providing easier access to voting and, in a handful of cases, imposing more restrictions on guns.

The values that underpin these governing strategies reflect contrasting political visions, and the differences can be seen in stark terms in the states. In a red state such as Texas, government exists mostly to get out of the way of the private sector while holding to traditional social values. In blue states such as California and Maryland, government takes more from taxpayers, particularly the wealthy, to spend on domestic priorities while advancing a cultural agenda that reflects the country’s growing diversity.

The recent gridlock in Congress has been blamed on political polarity — increasingly antagonistic political ideologies among Democrats and Republicans. But the phenomenon isn’t unique to Washington: Today, three-quarters of the states are controlled by either Republicans or Democrats, more than at any time in recent memory.

The alternative models on display in the states have triggered a competition for bragging rights about which would be better for the nation as a whole — a debate that is likely to intensify nationally in forthcoming elections.

Louisiana Gov. Bobby Jindal (R), coming off a year as chairman of the Republican Governors Association, has been a tireless proselytizer for his party’s conservative approach. Red states, he said, are “doing better economically, they’re doing better with credit ratings, they’re doing better with people moving into their states. . . . I’ll sit here all day and talk to you about how Republican policies and Republican-led states are doing better.”

Illinois Gov. Pat Quinn (D), who has moved Illinois in a progressive direction, countered that the Republican model threatens to leave too many people behind. “We’re not Pottersville, and we don’t intend to be Pottersville,” he said in a reference to the mean-spirited and miserly villain in the movie “It’s a Wonderful Life.” “There is a choice between a Bedford Falls that cares about your neighbor and the scorched-earth, don’t-care-about-your-neighbor policy of Mr. Potter.”

Single-party control

Today, 37 of the 50 states are under unified party control. Republicans hold the governorship and majorities in both chambers of the legislature in 23 states; Democrats have full control in 14 states. In 12 states, power is divided between Republicans and Democrats. (The other state, Nebraska, has a nonpartisan, unicameral legislature, although the governor is a Republican and the legislature is conservative.)

Justin Phillips, a political scientist at Columbia University who has written extensively about state government, said the degree of unified party control in the states is greater than at any time in more than half a century.

“This allows governors to behave very differently than they do under divided control,” Phillips said. Acknowledging that the parties long have had different philosophies about how to govern, he added: “The difference between what Democrats want and what Republicans want is growing. With unified party control, they don’t have to compromise.”

The National Governors Association once was an arena where governors of both parties came together to find consensus. But Ray Scheppach, who spent three decades as the organization’s executive director, said the governors’ partisan organizations — the Republican Governors Association and the Democratic Governors Association — now dominate, producing a sea change in the way states are being governed.

“They used to be governors first and Democrats or Republicans second,” Scheppach said. “Now they’re Democrats and Republicans first and governors second. In my mind, that’s a huge change.”

Widespread unified control in the states represents a significant shift over a period of three decades. After the 1980 elections, 24 states were under unified control. A decade later it was 20, and after the 2000 election it was only 21. Since then the states have been moving toward more unified control, with the biggest changes taking place in the past half-dozen years as partisan lines have hardened and split-ticket voting has declined across the country.

Control in the states today is more closely aligned with voting patterns in presidential elections than in the days when conservative Democrats dominated state and local elections in the South and moderate Republicans held greater sway in the North.

Karl Kurtz, a political scientist at the National Conference of State Legislatures, noted in an article published this year that Republicans control both houses of the legislatures in 22 of the 24 states carried by Mitt Romney in 2012 and that Democrats hold majorities in 18 of the 26 states won by Obama.

The eight Obama states that have full or partial Republican control are or recently have been presidential battlegrounds. These are Florida, Iowa, Michigan, New Hampshire, Ohio, Pennsylvania, Virginia and Wisconsin.

Two decades ago, when politics were not as polarized, governors were more inclined to work cooperatively with legislators of the other party, in part as an acknowledgment of the disparate views of the entire citizenry of their states.

“This picture of Republican-controlled states doing exactly the opposite of what Democratic-controlled states do on these issues is relatively recent,” Kurtz said. “Even in past generations, even when they had the hammer, when they had unified government, when they might have had a supermajority or veto-proof majority control, I think there was more of a tendency to negotiate with the minority than there is today.”

The risk is that with unified control, governors and their like-minded legislators push beyond the views of their citizenry, particularly in states where public opinion is more evenly divided.

Phillips and Columbia colleague Jeffrey R. Lax argued in a paper published in the American Journal of Political Science that elected officials in states with unified control can overshoot public opinion. “The net result is that state policy is far more polarized than public preferences,” they wrote.

The most obvious example of this is Wisconsin, a state Democrats have carried in every presidential election since 1988 (although several of those outcomes were among the closest in the nation). After his election as governor in 2010, Republican Scott Walker, with the backing of a GOP-controlled legislature, moved swiftly to implement a conservative agenda that included significant restrictions on collective-bargaining rights for most state workers.

The policies sparked widespread protests and ultimately a recall election in 2012 that Walker survived. The state remains deeply polarized, and Walker, a prospective 2016 presidential candidate, remains firm in his convictions, with a new book titled “Unintimidated.”

In Ohio, which Obama carried in 2008 and 2012, Republican Gov. John Kasich and his legislature triggered a similar backlash over changes in public employees’ collective bargaining and over voting laws. Ohio voters repealed restrictions on collective bargaining for public employee unions a year after Kasich’s election. Later, faced with another threat of a citizen veto, the legislature rolled back some voting-law restrictions.

Going separate ways

In many more states, however, citizens are being governed by a philosophy and a set of policies that conform more closely to public opinion within their borders. That has accelerated the trend toward more-partisan governing, and as Ronald Brownstein and Stephanie Czekalinski wrote this year in National Journal, it is sometimes “straining the boundaries of federalism.”

Over the past three years, Obama’s Affordable Care Act has been the most ideologically divisive issue across the country. The law envisioned that the states would establish marketplaces, or exchanges, to facilitate the purchase of health insurance.

But 27 states opted not to do so in any way, throwing responsibility on the federal government. All have Republican governors, Republican legislatures or both. Of the states that took full responsibility for an exchange, two-thirds are under unified Democratic control and almost all the rest have divided government. (There are seven states in partnership with the federal government.)

The law also expanded access to Medicaid, with the federal government providing the states with more than 90 percent of the funding over the first nine years. Democratic-led states leaped at the opportunity, but 23 states have declined — three-quarters of them under unified Republican control when the decisions were made.

Some Republican governors have bucked that trend. Eight states with Republican governors or unified Republican control have decided to enter into the expanded Medicaid program.

The latest to join was Iowa, where Republican Gov. Terry Bran­stad worked with leaders in both parties in a divided legislature. Earlier, in Ohio, Kasich had to overcome resistance from Republican legislators. He found a route around the legislature that put his state in the program, arguing that it was good for the state and its low-income residents.

Governors of both parties often cite the same priorities when they talk about their agendas: job creation, education, transportation and health care. But policies have differed, particularly as they have addressed budgetary pressures during the slow recovery after the 2008 recession.

Tax policy is one area that often has divided Republicans and Democrats. The American Legislative Exchange Council, a conservative group that has offered legislative models for lawmakers, cites 18 states as having cut taxes this year. All but two have Republican governors, and those two — Arkansas and Montana — have Republican legislatures.

Democratic governors have gone in the other direction. Maryland, under Gov. Martin O’Malley, raised taxes on the wealthy. California Gov. Jerry Brown won voter approval last year for a major tax increase on the rich.

On education, Republican-led states have pushed for charter schools and more choice for parents in lieu of ever-greater spending. They say their blue-state colleagues are too constrained by the power of teachers unions to be as bold in their efforts. Democrats say Republicans have been too willing to squeeze funding for schools.

The minimum wage is another point of divergence. California, Connecticut, New Jersey, New York and Rhode Island have increases pending. In New Jersey, where Democrats control the legislature, voters in November approved a constitutional amendment increasing the state minimum wage. Republican Gov. Chris Christie opposed the amendment.

Red and blue states also have gone in different directions with labor relations, with red-state governors and legislatures moving to restrict collective-bargaining rights for public employee unions and others approving right-to-work legislation.

Michigan is a state synonymous with union power and one that has consistently voted for Democratic presidential nominees since 1988. But the GOP-controlled legislature last year approved a right-to-work law. When Republican Gov. Rick Snyder signed it, he said: “I don’t view this as anti-union at all. I believe this is pro-worker.”

Pensions have strained the budgets of most governors. Red-state governors have trumpeted their efforts to revamp public employee pension and benefit packages, but blue-state governors have been forced to act as well, despite ties to organized labor.

According to analysts at both Morningstar and Moody’s, there is no clear red-blue pattern to the problems states face on the pension front or to actions taken to solve those problems.

Illinois had perhaps the most severe pension problem in the country and seemed politically incapable of dealing with it. But Quinn and the legislature reached agreement recently on what Moody’s called “the largest reform package” in the country. If fully implemented, the analysis said, the deal would substantially reduce a problem that had resulted in five credit downgrades for the state.

Culture wars continue

Social issues have produced an even starker dividing line between red and blue states.

Abortion wars in Texas drew national attention this summer when state Sen. Wendy Davis (D) filibustered against a bill to restrict abortions after 20 weeks of pregnancy. The filibuster helped launch Davis to a candidacy for governor in 2014. But in conservative Texas, she and her allies ultimately failed to block enactment of the bill, which was championed by Gov. Rick Perry (R) and the GOP-controlled legislature.

Texas was hardly alone among red states in moving to restrict abortion rights. Elizabeth Nash of the Guttmacher Institute, which tracks abortion issues across the country, said that in 2013 there were 64 restrictions approved in the states. Of those, 53 were in states where Republicans control both the legislature and the governor’s office. Ten came in states where the Republicans have partial control of the government.

“In general, if there is Republican control, then abortion restrictions are on the table and able to be enacted,” she wrote in an e-mail. “When Democrats are in charge then abortion restrictions are not very likely.” Nash noted that California was the only state to approve expanded access to abortion services.

The Supreme Court gave same-sex marriage a boost this summer in a pair of rulings but stopped short of legalizing such unions across the country. That has left the issue to the states, where action follows a distinct red-blue pattern.

Same-sex marriage is now legal in 17 states and the District of Columbia. Where it has become legal by popular vote or action by a state legislature, Democrats control the levers of government.

In some other states, the courts have moved to sanction such unions. In recent weeks, same-sex marriages became legal in two more states — New Mexico, where control of government is divided, and Utah, long a Republican stronghold. In both cases, the change came from court rulings.

There have been political repercussions in two other states with divided control of government after courts stepped in to legalize such unions.

After the Iowa Supreme Court acted in 2009, its ruling triggered a major political reaction. Voters subsequently removed three judges who had supported the ruling. A fourth survived his election in 2012.

In New Jersey, the issue produced a different reaction. Same-sex marriages became legal there in October by court action. Christie opposed the change, but with Election Day only a few weeks off, he chose not to buck public opinion and withdrew the state’s appeal to the court action.

Public opinion has shifted dramatically on this issue, but some red states are still moving to put prohibitions in their constitutions. North Carolina, which has been a presidential battleground in the past two elections but where a Republican governor and legislature have moved decidedly to the right, approved such an amendment in the spring.

Many other states have such prohibitions written into their constitutions, and they are likely to become the next front in the culture war over same-sex marriage.

The mass shooting last December at Sandy Hook Elementary School in Newtown, Conn., sparked calls for new gun-
control legislation, nationally and in the states. Obama’s gun initiative died in the Senate early this year, but new restrictions were enacted in eight states, seven where Democrats have unified control.

“I’ve been involved with state legislation for 18 years now,” said Brian Malte, senior national policy director at the Brady Campaign to Prevent Gun Violence. “2013 was by far the most successful year in terms of us passing proactive gun legislation.”

Andrew Arulanandam, director of public affairs at the National Rifle Association, said the pattern is fairly clear on gun legislation. Where control is divided or where Republicans hold power, “we were able to advance our agenda,” he said. Even in some blue states, the NRA was successful in defeating proposed restrictions.

Colorado passed new gun restrictions after the Sandy Hook killings and an earlier mass shooting in a suburban Denver movie theater. But the legislature’s action produced a backlash from pro-gun groups and citizens, resulting in the recall of two Democratic state senators, including state Senate President John Morse. A third who faced a possible recall resigned.

Voting laws have become another red-blue battleground. There are two trends visible in the states. Red states have moved to enact a series of restrictive laws, including those requiring ID cards to vote as well as laws that cut back on early voting.

“That trend has been almost exclusively in states that are red, where the legislature and the governorship are Republican,” said Wendy Weiser, director of the Democracy Program at the Brennan Center for Justice.

A countertrend has developed in blue and some red states, with legislators moving to make access to voting easier, through things such as online registration.

The red-blue hard sell

The debate over which approach works better is being fought with claims and counter claims, all buttressed with batteries of statistics: the number of jobs created, the rate of job creation, changes in median income, poverty rates or the percentage of the population without health insurance.

Some analysts who have studied the contrasting performances of states say government policy is only one factor and perhaps not as significant as a state’s history and culture. Michigan’s long economic decline came during periods of both Democratic and Republican governorships, for example. California rose under Democrats and Republicans before it hit budgetary and economic turbulence.

“It has almost nothing to do with any individual administration,” said Tyler Cowen, an economics professor at George Mason University. “I think of history as the number one factor. State government is significant but secondary.”

Still, Republicans have been more vocal about what they see as the superiority of their philosophy.

Louisiana’s Jindal says that, on average, unemployment is about a point lower in Republican-led states than in Democratic-led states. Of the 10 states with the lowest unemployment rates in November, five have unified Republican control, three are controlled by Democrats, one is divided and one, Nebraska, has a unicameral legislature. Of the 10 states with the highest unemployment rates, four are in unified Republican hands, two are under the control of Democrats and four are divided.

Among the 17 states that the Bureau of Labor Statistics says had statistically significant declines in unemployment over the past year, eight are controlled by Republicans, seven are controlled by Democrats and two have divided government. Two of the top three performers — North Carolina and Florida — are under GOP control while the other — New Jersey — has a Republican governor. In these 17 improving states, California’s unemployment rate, at 8.5 percent,was the highest.

Presented with some of those realities, Jindal said there are fairer measures of success than the unemployment rates. He cited overall job growth and, crucially, how businesses rank the states. He and other Republican governors point to Texas as the nation’s leader in job creation since the 2008 recession, and they credit low-tax, low-regulatory policies for the successes.

Jerry Nickelsburg, a professor at UCLA’s Anderson School of Management, said Texas’s success is clear. But he questioned whether the same model is successful in other states. “Texas does really well with GDP growth,” he said. “But then go to other low-tax, low-wage, weak-union states and you really don’t find them doing quite so well.”

Maryland’s O’Malley drew a different contrast between how Democrats and Republicans are governing, arguing that his state’s record holds up well when measured against red states. “The fundamental difference between most Democratic governors and most Republican governors has to do with ideology versus a more entrepreneurial approach,” he said. “Democratic governors exist in a reality-based world. We are not chained to ideology.”

Wisconsin’s Walker said the GOP’s small-government model is the surest way to economic dynamism. “You create a government that’s . . . mainly about helping government get out of the way,” he said. But he added a caveat. “I think government’s too big, too expensive, too involved in your lives,” he said. “But for the government that’s necessary, it should work. . . . That’s the challenge for Republicans.”

Perry, who is exploring a second presidential candidacy, has taken this fight into his opponents’ back yards. He has sponsored radio ads in or made forays to some Democratic-led states to encourage businesses to consider moving or expanding operations to Texas. asserting that the limited-government approach of Republicans has clear advantages over the Democrats’ model.

Illinois’s Quinn dismissed Perry as a “big talker.”

“I have read the entire book of Amos in the Old Testament,” Quinn said. “Amos was a working guy who took care of sycamore trees. One of his famous pieces of advice is, don’t afflict the poor. I think some of the policies of the governors on the other side are afflicting the poor.”

The coming national debate

California’s Brown ultimately finds all the gamesmanship tiring. “I think it’s hard to make these generalizations,” he said. “A lot of it is just boosterism when governors go around. They’re more like promoting their state to puff up their images. We [in California] have problems, and we’re solving them.”

One analyst who works closely with governors and who spoke on the condition of anonymity because he did not want to take sides in the debate, said, “I don’t know that anyone has a definitive measure to show your economic policy is better than mine.”

Perry argued that the red-blue contrasts are just what the Founding Fathers envisioned by giving states constitutional authority to chart their own destinies with economic and social policies that are tailored to their populations. “People in this very mobile society can go live where they’re most comfortable,” he said.

The next presidential campaign probably will revive the national debate about whether the country should move decisively in one direction or the other, particularly if a Republican governor becomes the party’s nominee.

But Thad Kousser, a political scientist at the University of California at San Diego, offered this caution to would-be contenders. “When a governor is running for president,” he said, “they push an ideological agenda that is tailored much more to the national primary voters in their party than it is to the average voter in the state. And they often crash and burn for that reason.”

Columbia’s Phillips said it is questionable whether there is an ideal model for the nation. “If the country had to live under one [red or blue] model, I think national politics would be as hostile, or worse, than it is today,” he said. Having divergent approaches in the states, he said, “defuses” some of the conflict at the national level. “It is what the framers of the Constitution envisioned.”

But Brown focused on one value of single-party dominance in an era of partisan divisions. “The main thing is to get stuff done,” he said. “You need a governing consensus. . . . You can’t govern as a constant bickering, debating society. Somebody must prevail over time to sustain any kind of momentum.”

That question could be at the heart of the debate in 2016. After years of gridlock, will people be prepared to move as decisively in one direction or the other in Washington as they have been in the states?