PRESIDENT OBAMA had plenty of nice things to say about equal rights for gay men and lesbians at Wednesday’s news conference. He rattled off his administration’s record, including making the determination that the Defense of Marriage Act (DOMA) is unconstitutional and would no longer be defended in court. And he said that the legalization of same-sex marriage in New York last week was “a good thing.” But what Mr. Obama didn’t say and steadfastly refuses to say is that he believes that gay and lesbian couples should be allowed to legally wed.

When asked about same-sex marriage last December, the president said that his views on the issue were “evolving.” At the time, this was viewed as a step forward. Not anymore. Not after New York became the sixth state to legalize gay marriage (as the District has also done). Not after the leadership shown by Gov. Andrew Cuomo (D) to get it done. With 53 percent of the American people in separate polls by The Post and Gallup supporting gay marriage, Obama is effectively behind the country on this equal rights issue.

The president was right to laud the marriage-equality debate sparked by the actions of his administration, the states and the courts. He was right to say, “We are moving in a direction of greater equality.” And he was correct when he said that “the president . . . can’t dictate precisely how this process moves.” Yet where he is wrong is in withholding his decisive voice on this issue. The opinion of the president matters. His speaking out in favor of gay marriage could push forward the broader acceptance that he says “is a good thing.” This could be of great significance, for example, in Maryland, where advocates are gearing up for a second shot at legalizing gay marriage next year. Mr. Obama’s clear voice and unambiguous stance could be what’s needed to ensure success.

Surely there are political considerations lurking in the background. With a presidential campaign that promises to be closer and more contentious than the one that got him elected four years ago, Mr. Obama and his team might be reluctant to embrace a controversial social issue when the economy and jobs are of paramount importance to voters.

At some point, though, doing the right thing must trump politics. If Mr. Obama does come out in favor of gay marriage, his base would surely rally around him. And all supporters of gay rights should be girding themselves for battle with those who would use the president’s position to deny him a second term.

The first question at the news conference was about Republican recalcitrance on tax increases. “Hopefully leaders at a certain point rise to the occasion and do the right thing for the American people,” Mr. Obama said. Later, he would say, “If you know you have to do something, you just do it.” The same words apply to him on marriage equality.

So just do it already.