Republicans know that gay-bashing doesn't yield the same political gains as it did in the past, particularly among younger voters. Polls show that gay voters are more than willing to support Republican candidates if they exclude overt gay-bashing from their platforms. http://www.huffingtonpost.com/2010/11/05/gay-voters-republicans-doubled-2008_n_779111.html
Republican candidates are now making it their business to court gay voters.
http://www.azcentral.com/arizonarepublic/local/articles/0821gop-gayvote0821.html
The potential conservatism of gay voters shouldn't be underestimated. The legal battle against Don't Ask/Don't Tell was spearheaded by gay Republican lobbyists, The Log Cabin Republicans. It was, in my opinion, a militarist campaign suffused with patriotism and American exceptionalism.
The campaigns for Gay Marriage (something I support) have also veered toward the conservative often emphasizing commitment, moral values and family.
So Obama's recent position on the Defense of Marriage Act is less of a risk than most people believe. Riskier would be having that lucrative voting block stay at home or defect to the other side.
fm