Michael Barone, who labels himself a supporter of same-sex marriage, uses his latest column to explore the political implications of President Obama’s recent announcement about gay marriage.

Obama was facing a tough political choice on the issue. He needs two groups of voters who often don’t turn out in large numbers to do so this fall: blacks and young voters. Young Americans tend to favor same-sex marriage by wide margins. Black Americans have tended to oppose it by wide margins (though not as wide this month in North Carolina, it seems, as in California in 2008, where 70 percent voted against it).

By saying he was still against same-sex marriage but was “evolving” on the issue, Obama sought to avoid riling black voters while giving a wink to young voters, hinting he shared their view.

He was in the position of the old-time pol who said, “Some of my friends are for the bill, and some of my friends are against the bill, and I’m always with my friends.” …

… I think Obama’s switch will help him significantly with young voters. And he has been doing conference calls with black ministers to mollify them in the hope they’ll turn out their followers despite his stand.

But Gallup reports that 26 percent of voters say they’re less likely to vote for him because of this issue, exactly twice the 13 percent who say they’re more likely to do so.

And the CBS/New York Times panel-back showed 67 percent saying he made his decision “mostly for political reasons,” while only 24 percent say he did so “mostly because he thinks it is right.”

That’s a harshly negative result. It suggests that most voters see the president, on this issue at least, as opportunistic rather than sincere. That’s good reason for panic.