A new Washington Post/ABC News poll finds that support for gay marriage has hit a new high, with 59 percent of Americans backing it, while only 34 percent are opposed. The poll also finds that 50 percent believe the Constitution’s “equal protection” clause guarantees the legal right to marry — suggesting public support is growing for the argument that observers say will hasten the demise of legal barriers to gay marriage nationally. This could weigh on the Supreme Court.

Republicans are alone here: They oppose legal gay marriage by 54-40; and they don’t believe the “equal protection” clause guarantees the legal right to marry by 54-38. Majorities of independents and moderates are in the Yes camp on both.

Note the religious breakdown: White evangelical Protestants overwhelmingly oppose gay marriage, by 66-28. By contrast, white non-evangelical Protestants support it by 62-27, and white Catholics support it by 70-26.

Mike Huckabee has warned that if the GOP embraces gay marriage, “they’re going to lose a large part of their base because evangelicals will take a walk.” And indeed, the GOP has not meaningfully evolved on gay marriage. While many Republicans condemned the Arizona anti-gay bill, the House GOP still won’t vote on the Employment Non-Discrimination Act, which would ban anti-gay hiring discrimination. Meanwhile, so few Republican lawmakers have embraced gay marriage that when one steps forward and does so, it’s big news, a veritable act of political heroism.

Meanwhile, opposition to gay marriage among Republicans seems to be concentrated among the Tea Party. According to the Post polling team, Republicans and GOP-leaning independents who support the Tea Party oppose gay marriage by 54-38. By contrast, non-Tea Party Republicans and GOP-leaners support gay marriage by 57-36. Tea Party Republicans are often said to be more libertarian-leaning on social issues than other segments of the GOP base (such as evangelicals), but a majority of them still opposes same-sex marriage.

All of this sheds more light on the question of whether Republicans need to evolve their party to keep in step with diversifying America. As Ron Brownstein and Dem pollster Stan Greenberg have suggested, Dems may continue to profit politically in national elections from the GOP inability to broaden its appeal to segments of the electorate that include “diverse America” and the portions of white America “who are comfortable with diverse America.” If this is right, then on gay rights, the GOP continues to be captive to a base that shows no signs of wanting to move into that latter category.

* THE LATEST ON THE FLORIDA SPECIAL ELECTION: The Associated Press pinpoints the crucial dynamic to watch for in the remaining six days in the special election in Florida’s 13th district:

As of Monday, 53 percent of the registered Democrats who had requested mail-in ballots had returned them, while 52 percent of the Republicans had. A total of 78,605 Republicans requested ballots by mail, while 72,068 Democrats and 43,468 voters registered as independents or to other parties had requested the mailed ballots…”What this race comes down to is how effective the Democrats and Republicans are in chasing their party’s mail-in ballots,” said Dan Smith, a political science professor at the University of Florida.

These numbers suggest Republicans are underperforming so far relative to what they need, but Republicans will end up with a big registration edge. This underscores that the outcome will be determined largely by turnout, and since turnout is quirky in special elections, we shouldn’t over-interpret the results.

* OUTSIDE MONEY POURS INTO FLORIDA RACE: ABC News recaps all the latest developments in the special election, and notes:

According to information provided by Open Secrets, outside spending in the race has reached upward of $6.6 million, the majority of which came from donations to Jolly’s campaign through contributions from the National Republican Congressional Committee and U.S. Chamber of Commerce.

Notably, the NRCC and Chamber ads have focused heavily on Obamacare. That said, Alex Sink did not vote for the law, so even if she wins, I’d be cautious about reaching any firm conclusions about what it will mean in November for Senate Dems who did vote for it.

* OBAMA FACES PRESSURE ON DEPORTATIONS: Robert Menendez, the only Hispanic Dem Senator, last night called on Obama to use executive authority to slow deportations of undocumented immigrants:

“Just two weeks ago, my office had to ask ICE to reconsider the unfair deportation of a New Jersey man with no criminal record and three U.S. citizen children— one of whom is very ill and in medical need of his father,” he said. “Does anyone think that an upstanding citizen and New Jerseyan like Carlos should be deported before a criminal is deported?”

If the discharge petition Dems will employ to force a House vote on immigration reform fails, the pressure will rapidly intensify on the President to act, since it would confirm once again Republicans have no intention of acting this year. You could see more senior Dems in Congress stepping forward as Menendez has now done.

* WHITE HOUSE HAS FEW OPTIONS ON UKRAINE CRISIS: Peter Baker has a useful overview detailing the specific tools the White House might use to contain or reverse the Ukraine crisis, including signing an executive order creating sanctions against Russian officials and organizations, though European leaders appear reluctant to go along with the toughest sanctions. What lies ahead:

White House officials said they saw three possibilities. The first would be a Russian escalation into eastern Ukraine, one they hope Mr. Putin was signaling he would not pursue. The second would be Russia deciding to stay put in Crimea, either through annexation or through de facto rule. The third would be Russia taking what American officials call an offramp, agreeing to let international monitors replace Russian troops in the streets to guard against any attacks on Russian speakers and accepting the Ukrainian government that emerges from the May elections.

* GOP ESTABLISHMENT WINS IN TEXAS — OR DID IT? Senator John Cornyn and GOP Rep. Pete Sessions easily prevailed over Tea Party challengers last night, an outcome that is being heralded as a victory of the GOP establishment over insurgents. But the First Read crew provides the key context (no link yet):

 The GOP establishment largely won the battle last night, the Tea Party has already won the war. Every Republican running for office — up and down the ballot — did so by running hard to the right and hard against President Obama (even in races that have nothing to do with the president)….Bottom line: Establishment Republicans have figured out how to survive (for the most part) in these primaries, but the question is whether this has been good for the party in the long run.

* DEMS STILL PUSHING ON UNEMPLOYMENT INSURANCE: With Dems still trying to find a way to extend unemployment benefits, CBS News reports that both sides are still haggling over procedural matters:

“If we are not able to offer amendments, then there is now way that this is ever going to pass,” Sen. Susan Collins, R-Maine, one of the Republicans working with Democrats on the issue, told CBS News. “It’s just not right. Many of us think that there needs to significant reforms.” Collins said she drafted an amendment that would give states the option of linking the benefits to a training or volunteering requirement. She also said that many Republicans don’t consider the farm bill a realistic cost offset.

Putting aside Collins in particular, it’s just impossible to take GOP objections to procedural matters and proposed pay-fors seriously at this point. One party wants to extend benefits; the other doesn’t; and Republicans just want to obscure this basic difference by getting folks to blame failure on “Washington.”

* AND TODAY’S PLUM READS: Jonathan Cohn has a must-read on the folly of pundits dismissing Obama’s budget as “irrelevant” because it stands no chance of passage; as Cohn notes, voters deserve a clear picture of both sides’ priorities in an election year, as well as to understand what each side will do once the current sequester-easing budget deal ends.

Sahil Kapur has a fascinating interview with Kentucky Attorney General Jack Conway on why he won’t defend the state’s ban on recognition of out-of-state gay marriage, even though it may run counter to the voters there.

What else?

Greg Sargent writes The Plum Line blog, a reported opinion blog with a liberal slant -- what you might call “opinionated reporting” from the left.