Rick in Casablanca said "We'll always have Paris". Less charmingly, the Republicans seem to believe that, whatever bad things are happening to them, they'll always have the gay marriage issue to fall back on. Hence, the president's eagerness to trot out his support for a constitutional amendment banning gay marriage at a time when his credibility is taking hit after hit, from AWOL to WMD.

How justified is their confidence in the political elixir of gay marriage? In DR's view, not much.

Start with public views on a constitutional amendment to ban gay marriage. Recent polls tend to show that, while the public is opposed to legalizing gay marriage, it is evenly divided on the question of a consitutional amendment. The latest Gallup poll, for example, has it dead-even, 47 percent for/47 percent against. Interestingly, that split is actually a little bit more favorable than it was in July of last year, the last time Gallup asked the question, when 50 percent said they were in favor of an amendment, with 45 percent opposed.

The Gallup poll also finds that the issue of same-sex mariage ranks dead last--14th of out of 14--in a long list of issues respondents were asked to evaluate for their importance in affecting their presidential vote.

The latest Newsweek poll also finds the public about split on a consitutional amendment--47 percent for and 45 percent against. But political independents, consistent with a long-standing pattern of relative liberalism on gay rights issues, are substantially more liberal than the public as a whole: they oppose a constitutional amendment by 53 percent to 40 percent.

Other polling data show that independents are also more liberal the the public as a whole on same-sex civil unions (which they tend to support) and on legalizing gay marriage (where they are split about evenly).

But if independents are a problem with this particular line of GOP attack, young voters are even more so. Their views are gay rights issues are conspicuously and unambiguously liberal. For example, even on the contentious issue of gay marriage, young Americans (18-29) favor allowing such marriages by 13-20 points in recent polls.

What this means, of course, is that attempts by the Bush campaign to inflame the issue of gay marriage around a constitutional amendment are virtually guaranteed to alienate large numbers of independent and young voters, when both critical groups of voters, as DR as repeatedly argued, are already leaning Democratic. To reach these voters, without whom Bush will have a difficult time winning re-election, the Republicans needs to shore up Bush's image as a tolerant, compassionate conservative not damage it even further.

And what if the Democrats counterattack by saying that a national constitutional amendment is unnecessary and punitive and that states should make their own laws on the issue (as vice-president Cheney, who has a gay daughter has famously advocated)? Then the GOP difficulties on the issue intensify because, according to a January ABC News/Washington Post poll , the public supports the state law approach over the national constitutional amendment approach by a 58 percent to 38 percent margin. And that margin is 60 percent to 38 percent among independents and more than 2:1 (67 percent to 32 percent) among 18-29 year olds.

In short, they may find the gay marriage elixir just gives them another headache.

Note: The just-released ABC News/Washington Post poll, which typically runs high on Bush's approval rating, has his job rating down to 50 percent and has him losing to Kerry by 9 points among registered voters. More on this poll tomorrow.