President Obama's personal embrace of gay marriage could negatively affect his prospects for re-election in subtle ways. But only on the margins, which of course is where close campaigns are won and lost.
The New York Times on Friday said Obama moved quickly to take advantage of the development in Seattle and Hollywood fundraisers. Still, support for gay marriage in those communities is an open-and-shut case, as in urban centers of New York and Massachusetts.
What net added votes Obama will harvest nationally from his declaration could be far under the radar, as he had already signaled his strong support for the gay movement by getting Congress to repeal "don't ask, don't tell" in the armed forces.
The biggest question for the president today is whether attitudes on same-sex marriage in a dozen so-called swing states have evolved as quickly as his. What some called overdue fairness, others saw as alarming radicalism.
Ten of these states held referendums on the question in the last decade, and they banned the practice by telling majorities. The most recent was in North Carolina last week, where a ban got 61 percent. It was closer in Virginia: 57 percent in 2006.
Ohioans are collecting signatures for a Freedom to Marry referendum for next year, to overturn a ban approved by 62 percent eight years ago.
In the opposite direction, Iowa's high court sanctioned same-sex marriages, but traditionalists are trying to call a referendum to overturn the ruling.
How Obama's plunging into an emotionally charged issue will help him in 10 battleground states that already cast negative votes needs to play out.
Then there is the president's minority base. The influence of Obama's historic announcement among church-going blacks and Hispanics will be untraceable until the exit polls of Nov. 6. Obama had solid race-based backing from them in 2008, but enthusiasm may have cooled because of persistently high unemployment in city centers and the fact that he has had no policy to do anything for the cities economically.
Will black and Hispanic clergy, who helped rouse his 2008 vote, reflect the same enthusiasm this time? Very few of them support same-sex marriage.
Finally, there is the president's comment that his support is only "personal." A president can't say anything personal on public policy. Obama personally nullified federal enforcement of the Defense of Marriage Act that says no state need recognize same-sex marriages conducted in another state.
His announcement will only add to fears among traditional Catholics and Evangelicals that an attorney general in an Obama second term will move against clergy who teach against gay marriage, branding them as purveyors of hate speech. The administration has already aggressively bid to shape health and adoption practices in church-related institutions.
While the president promised he won't push same-sex unions into the Democratic Party platform, others will try it; and add that proposition to the litmus tests applied to Democratic prospects for the Supreme Court.
This could play into Republican presidential candidate Mitt Romney's hand. Catholics and Evangelicals suspicious of his Mormonism may now warm to him on this front. Romney's backers might also claim that Democrats now want the federal hammer to not only impose health insurance on those who don't want it, but to reorder society.
Taking advantage requires Romney's ability to do it -- particularly to survive an ugly report, if true, that he rounded up classmates to help him haze, really to bully, a prep school schoolmate who turned out to be gay.
Though the reported incident was in 1965, it shows a repulsive reflex in a man seeking power.