On Monday, Rep. Barney Frank, D-Mass., told the Washington Blade that the Democratic Party's 15-member platform drafting committee has approved a plank supporting gay marriage for the party's upcoming convention. "There was a unanimous decision in the drafting committee to include it in the platform," Frank told the gay newspaper.

The committee made its the decision at a weekend meeting in Minneapolis. Before the unanimous vote, members heard testimony from several witnesses who urged the party to adopt the pro-gay-marriage plank. According to a party source, there were no witnesses who testified in opposition to making gay marriage part of the party platform.

There is no such unanimity among Democrats as a whole. While a Gallup Poll in May found Democrats support gay marriage by 65 percent to 34 percent, that 34 percent means one in three Democrats opposes what will surely be one of the highest-profile planks of the party's platform. That is significant opposition -- and nothing like the groupthink that apparently prevailed in the Minneapolis committee room.

It didn't take Republicans long to see opportunity in the Democrats' decision. Shortly after the news came out, a spokesman for the National Republican Senatorial Committee sent a press email highlighting a recent Wall Street Journal article that listed some Democratic senators running for re-election who have publicly distanced themselves from President Obama's support of gay marriage. Missouri's Claire McCaskill, Pennsylvania's Bob Casey, West Virginia's Joe Manchin, Florida's Bill Nelson -- all have laid low on the issue. Now that will be harder to do.

Republicans were perfectly happy to watch Democrats raise the profile of gay marriage, which usually ranks low among the public's concerns and has never been approved in a statewide vote. "Moving this issue to the forefront has the potential to create two problems for 2012 Democratic congressional candidates," said a senior GOP strategist in response to an email question. "First, it shows a further distraction by national Democrats when it comes to jobs and the economy, and that's where Republicans have a laserlike focus. Second, it creates a very uncomfortable intraparty dynamic for Democrats who have not endorsed same-sex marriage because they recognize the political peril this issue presents in their respective states. So Republicans are content to watch this very uncomfortable dynamic play out and distract Democrats in the weeks ahead."

That's far different from the kind of talk that prevailed in Minneapolis. "For Democrats, support is no longer a risky proposition," said Marc Solomon, national campaign director of the activist group Freedom to Marry, in testimony before the drafting committee Friday. "Instead, it's becoming increasingly difficult both morally and politically to justify not supporting marriage for gay couples."

Tell that to McCaskill and other endangered Democrats.

Along with the one in three Democrats who oppose gay marriage, Gallup found that 40 percent of independents oppose it, too. After its May poll, Gallup assessed how Obama's change in favor of gay marriage might affect his re-election prospects. The key to such an assessment, Gallup suggested, lies in the views of independents and Democrats whose support for Obama is a little shaky.

"Specifically, 23 percent of independents and 10 percent of Democrats say it makes them less likely to vote for Obama, while a smaller 11 percent of independents and 2 percent of Republicans say it makes them more likely to vote for Obama," wrote Gallup's Jeffrey Jones. "Those figures suggest Obama's gay marriage position is likely to cost him more independent and Democratic votes than he would gain in independent and Republican votes, clearly indicating that his new position is more of a net minus than a net plus for him."

Now Obama's party has decided to go with him. Democrats in Senate and House races in states with high opposition to gay marriage will not only have to distance themselves from the president but from their party as well.

The Democratic National Committee said nothing about the story on Monday. But the Washington Blade reported that the party's draft platform will not only support gay marriage but will specifically reject the Defense of Marriage Act, which allows states to refuse to recognize gay marriages from other states. So by September the official Democratic position will likely be to support gay marriage, everywhere, now.

A Democratic Party source notes that the platform draft still has to go before the party's full platform committee in Detroit two weeks from now, and then has to be approved by the delegates at the national convention in Charlotte in early September. But there is no evidence it will be derailed. Thanks to the Democrats, gay marriage could play a bigger role in the campaign than anyone thought.

Byron York, The Examiner's chief political correspondent, can be contacted at byork@washingtonexaminer.com. His column appears on Tuesday and Friday, and his stories and blogposts appear on washingtonexaminer.com.