I was out and about on Wednesday when an alert on my iPhone popped above the background picture to tell me that President Obama had publicly endorsed same-sex marriage. (Technological things like this still amaze to me.)

I’m embarrassed to say, my instant reaction was fear.

Considering I’ve written about this issue in some form three times, that surprised me.

I couldn’t recall a time when I was in such moral agreement with a politician’s decision and yet so politically worried about a stance he had taken.

“How will he win the election now?” I thought.

In the hours after and few days since, my feelings have tempered, but something still lingers.

Obama’s choice to support marriage equality has been pretty well received. The inadvertent bind Joe Biden put him in was handled about as adeptly as can be asked for, and the reaction from dozens of pundits, from Rachel Maddow to Shepard Smith, is heartening. In the numerous articles on the topic that I have read since Wednesday, most are neutral or favorable and are not sounding this as a death knell for a second term.

This is also not a strictly partisan issue. Many well-known and/or well-placed Republicans beat Obama to this spot. Still, people are closely watching the four Republicans in New York State who backed same-sex marriage last summer, and were profiled by Bill Keller in The New York Times Magazine last month. One of those four just decided not to run for re-election, partially because of his same-sex marriage stance.

Don’t get me wrong, I’m happy that Obama finished “evolving.” Any way you slice it, it’s a big deal. There’s no doubt that the president and supporters of marriage equality are on the right side of history, and not just from an ethical standpoint. Polls increasingly show Americans are on board with same-sex marriage.

Plus, the costs of being a same-sex couple who cannot marry are quantifiably much higher than those of a married man and woman. It seems pretty unfair to penalize someone financially by default for who they love.

But this is going to be a close election.

Every vote will make a difference in the nine battleground states that are expected to decide the winner.

It’s not about whether Obama will get more votes than (all-but-official GOP nominee) Mitt Romney among core demographics like women, African Americans, Latinos, young people, and college-educated whites; it’s by how much. The voting choices of a small percentage of people (several thousand?) in these states could decide the ballgame.

My fears have been subdued by some of the information that I’ve absorbed. The point most commonly made has been that the citizenry’s feelings on economic issues are far more likely to affect votes than social issues, notably among independents. Also, those who care enough about this issue and thought Obama secretly supported same-sex marriage anyway probably already jumped ship. (However, the GOP base may re-rile up because of this latest development.)

Plus, the reaction from the Democratic base has been huge: they are excited and donations are coming in. Will that translate into action and votes? (My chief concern in this election is complacency.) If so, in the end, it might turn the tide.

In addition, as I learned this week, “gays and lesbians themselves, and their families, are an important constituent group for Democrats. (They are more numerous, for instance, than Jewish voters.)” They will probably make a special point of voting now.

I can’t imagine that there will be instances where it does not matter, but the Obamans (David Plouffe, David Axelrod, et al.) are probably right there will be many more instances where it does not.

Hopefully, conventionally more skeptical older voters will at least hue to the line painted at the end of this piece, where “in a half-dozen interviews with Republicans who came to see Mr. Romney in Omaha on Thursday, not a single person voiced an objection at his decision not to dwell on the issue of same-sex marriage. ‘It’s none of my business. We don’t need to talk about it,’ said Mo Birkel, 70, a retired custodian from nearby Papillion, Neb., when asked about gay marriage. ‘I can’t say if I’m for it or against it, because I don’t know what my grandkids will be.’ ”

Why must I put this in political terms? Well, they matter beyond this issue. If this stance contributes to an Obama loss, it will probably go down as an unwise time to stand on an honorable principle, because it could lead to a backslide on numerous other issues nationally (climate change, health care, income inequality, immigration, the deficit, Social Security, etc.). If Romney wins, a possibly righter-than right (we should come up with a word for that) Congress will have in it a guy who, whatever he believes, wants to placate them.

Romney is against marriage equality. Plus, it’s conceivable that he is a dick. (Seriously, how do you forget about the time you cornered a suspected gay kid and cut his hair?)

Gallup now has results from its first poll measuring likelihood of voting for Obama given his support for same-sex marriage. It makes no difference to sixty percent of voters. However, among the remaining forty percent, twice as many are less likely to vote for him as are likely to vote for him. I wonder where those numbers will stand in early November.

Hopefully in six months’ time, we will be able to look back and say Obama’s was a courageous move that reminded voters why they sent him to the White House in the first place.

We’ll see. Until then, color me morally thrilled and politically ambivalent.