Forty-nine years ago this spring, as he proposed the landmark civil rights reforms of the 1960s, John F. Kennedy became the first president to declare that ending racial discrimination was a moral issue — that "this nation, for all its hopes and all its boasts, will not be fully free until all its citizens are free." Now Barack Obama has taken the next step in the unfinished journey toward that ideal: He cut through a cacophony of political advice, the calculus of pre-election caution, to become the first president to endorse marriage equality — and thus to affirm that gay rights are fundamental human rights.

It was fitting that this historic moment came, as JFK's did, from a president who himself had to overcome generations of prejudice to be in the White House in the first place.

Obama's decision, like Kennedy's, carries political risk — although it's worth remembering that in 1964, Barry Goldwater, who denounced the Civil Rights Act, lost in a landslide. Of course, circumstances are different now. The economy then was in the dawn of the longest period of prosperity on record. But there are also reasons to believe that Obama's position, both path-breaking and courageous, may prove to be right in politics as well as principle.

The president's decision to speak his belief, plainly, movingly, even if it is controversial, offers a stark contrast to Mitt's marathon flip-flopping and glaring insincerity.One early clue was Mitt Romney's tepid response. "Not on the ropeline," he answered a reporter asking about gay marriage, before later giving a pre-cooked statement that strained to sound moderate. He aims to benefit from the angry reaction of the religious right without echoing its intolerant excesses. Maybe he was conscious too that The Washington Post was about to report on his own anti-gay bullying as an 18-year-old at prep school. He has to wish that moderates and independents, who strongly favor marriage equality, will forget his pandering imitation of Rick Santorum during the primaries. The shape-shifting Romney, who once made the preposterous claim that he was "better" on gay rights than Ted Kennedy, sounded blandly modulated, even uncomfortable, as he commented on the president's decision. His tone suggests that for this election and this year, the consequences are more complicated than the one-dimensional notion that standing up for equality is a loser.

So what does Obama gain or lose here — beyond the distinction of writing a new chapter in the story of freedom?

Political opinion on marriage equality has moved at the political speed of light since 2004 — when Karl Rove and George W. Bush rode the issue to victory in state after state, including Ohio, where a wafer-thin margin of votes denied the presidency to John Kerry. No social issue has ever been so swiftly transformed — because of culture, demography, grassroots activism, and the overriding reality that once you know gay friends or relatives, it's hard to demonize them — or to defend the rank injustice of subjecting them to their own form of "separate but equal."

Not only do a majority of Americans now favor same-sex marriage, but 50 percent of Ohio Republicans favor it or civil unions.  And the Ohio outcome this time is likely to be shaped far less by Obama's position on marriage equality and far more by Romney's opposition to the auto bailout — which would have devastated the Buckeye State.

But couldn't the backlash against the president by gay-marriage opponents make just enough of a difference in just a few critical states?

Iowa and Virginia are frequently cited — but it very likely won't happen there. Obama has a 10-point lead in Iowa, where voters wouldn't do again what they did in the tea-fouled year of 2010, removing three of the state's Supreme Court justices who had joined a unanimous opinion striking down a ban on same-sex marriage. That decision still stands. And the old Virginia of Jerry Falwell is increasingly outweighed by the new Virginia that stretches from the Washington suburbs to Richmond.

Well, then, what about North Carolina, which just passed an anti-gay-marriage constitutional amendment? The implicit assumption is obvious, simple, and wrong. Here is the bottom line: In any swing state, voters for whom animus to marriage equality is the single, burning issue aren't casting a ballot for Obama anyway. If you are so intent on discriminating against gay Americans that this issue alone determines your presidential choice then you are almost certainly uncomfortable with an African-American in the White House.

Look at the absurd result in the May 8 Democratic primary in West Virginia — 40 percent for a convicted and incarcerated felon over the president. It's not the anti-government mood; West Virginia lives by federal largesse. It's anti-Obama, pure and simple, in a state that not long ago was pretty reliably Democratic. Such voters, there and elsewhere, won't be with the president — period.

Still, won't the issue fire intensity on the Right, driving up turnout for Romney despite lingering doubts about him? This is more a talking point than a political dynamic. Those who are polarized against Obama were never going to stay home. Indeed, whole swathes of the country, where aversion to same-sex marriage is matched by hostility toward the president, are beyond his reach. Nonetheless, he has an electoral college advantage with four or five paths to his 270 majority, while Romney's route is narrow and virtually singular.

The silliest argument of all is that Obama has damaged himself with African-Americans. More likely, his leadership will persuade more of the community to accept marriage equality — and that could matter in a state like Maryland, where the issue is on the ballot. African-Americans will show up at the polls in 2012 — for Obama. I would bet almost any amount that he will carry well north of 90 percent of their votes.

There is also a plus sign to this ledger. In terms of character, the president's decision to speak his belief, plainly, movingly, even if it is controversial, offers a stark contrast to Mitt's marathon flip-flopping and glaring insincerity. (There is a reason Americans tell pollsters they don't like the guy.)

Obama's candor will energize his base, especially the young, who overwhelmingly support marriage equality. Message to the religious right: Demography is destiny and you will lose this fight as the elderly opposition literally dies away. And mega-wealthy progressive donors, straight and gay, ought to be energized, too. Message to them: Stop wringing your hands about campaign finance reform and step in to counter the super PACs of Rove, the Koch brothers, and the rest. What the president just did powerfully proves that there's too much at stake to indulge the psychic satisfaction of empty sermonizing on the sideline.

Among progressives, John Kennedy was criticized for waiting two and a half years before sending the Civil Rights Act to Congress. Barack Obama has been criticized for dithering on same-sex marriage. But no one could doubt where Kennedy was headed after he sent the armed forces to integrate Ole Miss and sent his deputy attorney general to face down George Wallace at the schoolhouse door. And this president, who has repealed Don't Ask, Don't Tell, pushed through a hate crimes law, and refused to defend the shameful Defense of Marriage Act has now sealed his legacy as the champion of a 21st century birth of freedom in America.

That should be rewarded, not punished, in November — and I think it will be. Americans are a decent people; sometimes it just takes time.