It's nice to think that in a democracy, public policy will soon follow public opinion, with same-sex marriage becoming the norm, not the exception. But that's not how democracy works in a big, diverse federal system. On this emotional issue, the citizenry is divided, and marriage laws as well as politics will reflect that division for a long time to come.
The good news is that changing sentiments have already begun to alter the traditional conception of wedlock. Five states and the District of Columbia now allow gay marriage. Another 13 offer civil unions or domestic partnerships with some or all the benefits of marriage, according to Lambda Legal.
But the resistance is still strong and broad-based. The recent jump in support for same-sex marriage, Gallup notes, came entirely from Democrats and independents. Among Democrats, support now stands at 69 percent, with 59 percent of independents agreeing.
Republicans have not changed their minds. Only 28 percent are in favor -- the same as last year.
Realistic conservatives can't expect to prevail in the long-term battle for hearts and minds. Jim Daly, president of Focus on the Family, recently said, "We're losing on that one, especially among the 20- and 30-somethings: 65 to 70 percent of them favor same-sex marriage. ... We've probably lost that."
Public support for gay rights is even higher on other issues. Some two-thirds of Americans support granting gays access to civil unions. An ABC News/Washington Post survey last year found that 75 percent of Americans think openly gay individuals should be allowed to serve in the military -- including a majority of Republicans and white evangelicals.
Yet the two parties remain at odds over the issue. Although Democratic officeholders have been cautious in embracing same-sex marriage, they generally favor civil unions, at least. Barack Obama lifted the military's "don't ask, don't tell" policy on gays.
The 2008 Republican national platform, by contrast, asserted "the incompatibility of homosexuality with military service" and endorsed a federal constitutional amendment banning same-sex marriage.
The current crop of presidential candidates is almost unanimous in sticking to that hard line. The notable heresies: Former Utah Gov. John Huntsman signed a civil-union law, and Rep. Ron Paul of Texas voted to repeal the military ban.
Given the growing sentiment in favor of equality for gays, the Republican Party might seem to have two choices: Get in line or get beat. In fact, there is every reason to think that for the foreseeable future, the GOP will continue to reject gay rights -- and ample grounds, alas, to think it can do so without any real political penalty.
One reason is that most people who support same-sex marriage usually wouldn't vote Republican anyway. So Republicans need to make sure they retain their appeal to those (45 percent of Americans) who oppose it.
Another is that in many of the states where the GOP is strongest, gay rights are far less popular than they are nationally. In Texas, same-sex marriage gets only 30 percent support. In Utah, it's 22 percent. The states that provide it, by contrast, are mostly places where Democrats flourish, like Vermont and Massachusetts.
It's safe to assume that gay marriage will continue to spread in the coming decades, and it's safe to assume that opponents will not be able to get a constitutional amendment. But it's also safe to assume that many or most states will continue to forbid it. Connecticut and Iowa are one thing. Alabama and Arizona are another.
The other thing Republicans have going for them is that most people don't base their votes on this single issue. In the 2010 elections, 31 percent of gays voted for GOP congressional candidates.
Why? Because they place greater importance on other issues. Voting for a candidate is like choosing a cable TV package: Just because it's the best of the options doesn't mean you like everything it includes.
The recent emergence of a majority that favors same-sex marriage constitutes a turning point. So did the battle of Gettysburg -- and at that moment, the Civil War was only about half over. The outcome of the gay-rights fight may be discernible on the horizon, but there's a lot of fighting ahead.