One year out from the 2012 election, President Obama faces the most difficult reelection environment of any White House incumbent in two decades, with economic woes at the center of the public’s concerns, an electorate that is deeply pessimistic and sharply polarized, and growing questions about the president’s capacity to lead.

Those factors alone portend the possibility that Obama could become the first one-term president since George H.W. Bush, who was defeated by Bill Clinton in 1992 at a time of economic problems and similar anger with the political establishment in Washington. To win a second term, Obama probably will have to overcome the highest rate of unemployment in an election year of any president in the post-World War II era.

Last year’s midterm election victories have made Republicans eager for 2012. But public disaffection with the party and a muddled battle for the GOP nomination leave open the possibility that Republicans will not be able to capitalize on the conditions that have put the president on the defensive. Failure could produce the kind of disappointment that would trigger recriminations and an examination of the party’s priorities, tactics and leadership. Former Massachusetts governor Mitt Romney remains the candidate to beat, but so far he has not been able to consolidate support or generate enthusiasm in a party that is more conservative than he is.

What can be said at this point is that, after three years of pitched battles between Obama and congressional Republicans, the country is heading toward a high-stakes contest. Election 2012 will be a contest not just between two candidates but also between two starkly different views of the role of government that underscore the enormous differences between Republicans and Democrats.

Given the public mood and the president’s standing, the 2012 election will bring a dramatic shift from the hope-and-change enthusiasm generated by Obama’s first run for the White House. The race will be not only more competitive but also far more negative.

Geographically, the election will be won or lost in roughly a dozen states, beginning with most of those Obama took away from the Republicans in his first election but including a handful of traditional battlegrounds that may be more competitive than they were in 2008.

Independents, whose allegiances have shifted rapidly, will again hold the key to the outcome. But Obama’s hopes depend, too, on his ability to regenerate the coalition of African Americans, Latinos, younger voters and suburbanites that elected him. Among many of those groups, he has work to do.

Those conclusions are drawn from a new national poll by The Washington Post and ABC News and from interviews with elected officials, party strategists and senior advisers in the Obama and Republican presidential campaigns.

A pair of politicians who have served as two-term governors and as chairmen of their respective parties agreed that the president is looking at a difficult reelection campaign but still enjoys advantages inherent to any incumbent.

“When people look at the condition of the country, particularly the economic condition of the country, and then look at President Obama’s policies, which have made that condition worse, not better, I believe the majority will vote for a change, to get the country back on the right track,” said Mississippi Gov. Haley Barbour (R). “But it’s anything but a given, and you shouldn’t ever bet against an incumbent.”

Ed Rendell, the former governor of Pennsylvania, said there are three ways the president can win: through improvements in the economy, which he acknowledged look questionable, given forecasts; through the failure of Republicans to nominate a strong candidate; or through missteps by congressional Republicans that could alienate crucial independent voters. Though the path for Obama remains perilous, Rendell said, “I like the president’s chances.”

Steve Schmidt, who served as senior strategist to the presidential campaign of Sen. John McCain (R-Ariz.) in 2008, cast the election year ahead in dark terms.

“It’s a deeply pessimistic time,” he said. “Neither party is talking honestly or directly about the country’s problems and challenges. It’s going to be an extremely mean-spirited campaign, filled with nonstop attack ads. The whole focus will be on disqualifying the alternative, not on the country’s future. It will be very much the opposite of the hope-and-change theme of four years ago.”

In that context, the parties are already jockeying to frame the 2012 election, with Republicans aiming to cast it as an up-or-down vote on the president and Democrats wanting voters to see it as a choice between Obama and his opponent.

“President Obama’s failures have produced the greatest destruction of the middle class since the Great Depression,” said Stuart Stevens, chief strategist for Romney’s campaign. “The upcoming billion dollars of Obama campaign attack ads can’t distort the reality that this will be about President Obama’s record.”

Obama’s chief campaign strategist, David Axelrod, countered: “At the end of the day, presidential elections are always a choice, not a referendum. The American people take a hard look at each candidate and weigh their respective records, qualities, values and visions for the future. Not being the other guy isn’t enough.”

The mood of a nation

The new Washington Post-ABC News poll paints a stark portrait of an agitated electorate that is almost inflexibly divided, with voters awaiting the showdown between Obama and his eventual challenger. About three-quarters see the country as seriously off-track and nearly everyone sees the economy in bad shape.

Little more than a third of all Americans say they believe the economy has begun to recover, based on their own experience. That is markedly lower than the percentage of people who said they sensed the beginning of a turnaround at the end of Obama’s first year in office. Two-thirds doubt they can maintain their standard of living, and half worry they will retire without enough assets to last their lifetime.

Pessimism about the economy is matched by anger with the political system in Washington. An overwhelming majority of the people — eight in 10 — are dissatisfied with the way the federal government is working, including almost one-third — a record in Post-ABC News polls — who say they are angry about it.

Yet the consensus breaks down when people are asked to point fingers. Most Democrats blame Republicans for government missteps, while most Republicans say it is the president who is at fault. It is a pattern that colors political discourse in the country and almost all results in the poll.

The issue agenda for the coming election could not be clearer. The poll found that 56 percent of Americans cite the economy and jobs as their top voting issue in the upcoming election.

No other issue scored in double digits.

But Republicans and Democrats remain at loggerheads about what to do about the economy. About two-thirds of Democrats want fresh spending to encourage job creation, and a similarly high proportion of Republicans favor deficit reduction.

Americans split evenly over whether they trust Obama or congressional Republicans to handle the economy, create jobs and protect the middle class. Asked which party they would like to see control Congress after the next election, 44 percent say the Democrats and 41 percent say the Republicans.

The findings obscure recent slippage for Obama. After his jobs speech in early September, the president had a significant advantage over Republicans on that issue. That is now gone, despite a national campaign to pressure Congress to pass his bill. So, too, is his once-healthy lead on protecting the middle class.

The president’s overall job rating has been mired in the mid- to low 40s throughout the fall, with this latest poll showing 44 percent approving and 53 percent disapproving. Democrats believe Obama has begun to regain some of his footing, but his approval rating puts him well behind where the past four presidents running for reelection were at this stage.

Obama also has lost some ground in the way Americans view him. Those who say he is not a strong leader now constitute a bare majority — 51 percent — of the population, the first time he has dipped into negative territory on that crucial attribute. Criticism of Obama’s leadership is a key part of the GOP’s message in the campaign, and more than three-quarters of Republicans say he is not a strong leader, as do 53 percent of independents. A quarter of Democrats also agree with that assessment.

The Post-ABC poll measured Obama against Romney, businessman Herman Cain and Texas Gov. Rick Perry. One year out, Obama and Romney are essentially tied among registered voters and Obama is ahead of Cain and Perry. Democrats take heart from those kinds of findings, arguing that with such a bad environment, it is surprising that Obama isn’t running behind his potential opponents. Republicans think their nominee will be stronger after going through the primaries.

The battlegrounds

Until the Republican nominee is known, the contours of the playing field on which the general election will be fought will not be entirely clear. But there is widespread agreement across party lines about which states will determine who takes the oath of office in January 2013.

Republicans believe the electoral map of 2012 will look more like those of 2000 and 2004, which were two of the narrowest electoral victories ever, rather than 2008, when Obama won handily. Obama advisers and their allies say that whatever the map looks like, they will have more routes to the necessary 270-vote majority than the GOP nominee.

Democrats begin with a larger base, with the states they won in both of the past two presidential elections accounting for 246 electoral votes. In comparison, the states that Republicans won in both of the most recent elections account for 180 electoral votes. That leaves the nine states Obama took away from the Republicans — Colorado, Florida, Indiana, Iowa, Nevada, New Mexico, North Carolina, Ohio and Virginia.

Those nine states will be the first targets of the Republicans, and already they are putting Indiana in their column. Few Democratic strategists dispute that assessment — Obama won there by a single percentage point in 2008, and the state has reliably voted Republican in presidential elections for decades.

Of the remaining eight, Republicans see their greatest opportunities in two southern states Obama carried: North Carolina and Virginia. Obama advisers have a different view, arguing that the electorates in both states, which include sizable African American populations as well as significant numbers of younger voters and well-educated newcomers, are prime prospects for Obama’s candidacy.

Florida and Ohio, two of the remaining Obama takeaway states, have been the focus of pitched battles in the past three presidential elections. Both could be competitive again. Democrats believe Florida is the less difficult of the two, if only because of the growing non-Cuban Hispanic population and the opportunity to expand the electorate. Economic problems abound there, however, and Republicans made major gains in 2010.

Ohio is challenging for Obama because of the state’s relentless economic problems and because its electorate is older and whiter than in some other states. Republicans scored major gains in Ohio last year, including the election of Gov. John Kasich. But his first year has been turbulent, and he faces possible repudiation Tuesday when the state decides whether to repeal a GOP bill that narrowed the collective-bargaining rights of public employees.

Three other Obama takeaways — Colorado, New Mexico and Nevada — came in the Rocky Mountain West, a region that has become increasingly competitive as the size of the Hispanic population has grown.

Nevada is ground zero of the home foreclosure crisis and has the nation’s highest unemployment rate. Colorado also will be a challenging environment for Obama, though he has a template for winning based on the strategy employed last year by Sen. Michael F. Bennet (D), who survived in a tough year thanks in part to mistakes by his opponent.

Beyond the nine states that flipped between 2004 and 2008, several other states will be competitive. Three are in the industrial heartland: Michigan and Pennsylvania, which have voted for Democratic nominees in five straight presidential elections, and Wisconsin, which has done so six times in a row. But Republicans hope to put all into play next year.

Martin Frost, a former House Democrat from Texas and past chairman of the Democratic Congressional Campaign Committee, said the mood of the country could make this election unique.

“I don’t think you can put 2012 in any neat little box and compare it to any particular past election,” he said. “Fasten your seat belts.”

Rep. Tom Cole (R-Okla.) worries that it could be a repeat of 2004.

“It will be an intensely negative and bitter election,” he said. “And that will complicate things enormously for the winner in 2013, just as it did for [George W.] Bush in his second term.”

Given the state of the country, that is a sobering reminder that elections have consequences, and not just in who wins or loses.

Polling manager Peyton M. Craighill contributed to this report.