The same political climate that has hamstrung President Barack Obama on gay marriage is also preventing embattled Senate Democrats from stepping out on the hot-button social issue.

Though Obama campaigned in 2008 on a post-partisan platform, it’s clear that there are still “red states” and “blue states” when it comes to the debate, and whether Senators are willing to support gay marriage openly reflects that map.

“I’m 100 percent onboard, so I would say that’s why I talk about it because I think it is important,” Sen. Sheldon Whitehouse (D-R.I.) said as to whether he thinks it’s important for Democrats to talk about marriage equality.

Whitehouse, who is up for re-election this cycle, said he is “sure” many of his colleagues feel similarly. But any sort of gay marriage bill is likely to meet stiff resistance in the chamber, and Democratic leaders are unlikely to force their Members to take potentially politically explosive votes on something that would hit a brick wall in the House, too.

“It’s hard to see how you get that through the Republican filibuster blockade on our side, and good luck with the Speaker calling it up,” Whitehouse said. “I don’t think it would be anything more than a vain effort.”

For Democratic Senators from more conservative states facing more challenging re-election bids — such as Claire McCaskill in Missouri, Jon Tester in Montana and Bill Nelson in Florida — that effort likely is not worth having.

Without the administration taking a clear stand on the issue, Senate Democrats would only complicate the president’s current dilemma. Democratic leaders, who are often deferential to the president, are not likely to act in a way that would be destructive to the national campaign. Plus, Democratic lawmakers looking to prove their bona fides to the gay rights community can point to their efforts last year in repealing the military’s “don’t ask, don’t tell” policy. Senate Democrats have also recently pushed to add gay, lesbian and transgender individuals to the Violence Against Women Act, and they passed a hate crimes bill in 2009.

Still, McCaskill deflected on the question of whether Senate Democrats should bring up the issue. “It’s the president’s decision,” she said.

During the past week, the Obama campaign and the campaign of presumptive GOP presidential nominee Mitt Romney stumbled on the issue of gay rights. A top Romney foreign policy aide, who is openly gay, resigned after effectively being sidelined before his job even began. Though the Romney camp said it had no problem with the adviser’s sexuality, multiple media reports suggested that the Boston-based operation struggled to walk the line between supporting the staffer and not upsetting a conservative bloc uneasy with gays and lesbians.

Then on Sunday in an interview on NBC’s “Meet the Press,” Vice President Joseph Biden became the highest-ranking U.S. official to voice support for gay marriage. The Obama campaign went into defense mode, with Biden’s office issuing multiple statements and top Obama advisers trying to walk back the vice president’s remarks.

The next day, in another television interview, Education Secretary Arne Duncan voiced his support for extending marriage rights to same-sex couples.

That prominent Democrats support gay marriage is unsurprising. That they are voicing those opinions in a presidential election year when the president himself has not expressed them, however, has been creating a headache for Obama.

On Tuesday, North Carolina voters took to the polls to weigh in on a constitutional amendment banning same-sex marriage and ensuring that the only domestic legal union recognized in the state is between a man and a woman.

“I think a number of us have spoken out and made it clear our position. I support marriage equality. I think it’s the right thing to do,” said Senate Majority Whip Dick Durbin (D-Ill.), who added that he hoped Tar Heel State voters would agree.

Durbin, the No. 2 Democrat in the Senate, added that America’s leaders have a responsibility to set a tone on the issue, but he declined to say specifically whether the Senate should act on legislation.

“I think the American people are tolerant people, and if they have leaders who are tolerant, not only in their words but in their actions, that they will follow those leaders,” Durbin said.

But with Obama attempting to win several swing states in the South — such as Virginia and North Carolina — as well as blue-collar states in the Midwest, it’s doubtful that support for gay marriage will emerge in the president’s re-eleciton campaign at any point.

“I think we’re going to move toward that,” Durbin said of what might be included in drafts of the Democratic Party’s national platform. Durbin was a co-chairman of the 2000 drafting committee. But, he acknowledged, “I can’t tell you exactly what the words are.”