Will this year’s midterm elections feature a new raft of state ballot initiatives to ban same-sex marriage?

Definitely. Voters in eighteen states have already passed such bans, and the ballot initiatives have proven to be a major base-mobilizer for conservatives—so this year, there will be more. At least six states—Alabama, South Carolina, South Dakota, Tennessee, Virginia, and Wisconsin—will certainly hold referenda, and Arizona and Colorado are likely to do so as well. And given the success such measures have enjoyed at the ballot box, they will probably pass with strong majorities.

Yet these referenda—and the ongoing backlash they represent against the 2003 decision by the Massachusetts Supreme Judicial Court to legalize same-sex marriage—do not constitute the most interesting development in the emerging politics of gay marriage.

What development would that be?

A quiet countercurrent, driven by popular opinion, that’s making progress in several states, even in the face of the post-Massachusetts backlash.

Popular opinion? Isn’t gay marriage just the handiwork of “activist judges”?

Conservatives, including President Bush, often deride it as such. But the last few years have seen significant movement toward state recognition of same-sex relationships through normal democratic processes. In 2004, legislators in New Jersey and Maine passed domestic-partnership laws, joining Hawaii in formally recognizing same-sex partnerships and granting them certain rights associated with marriage. Last year, Connecticut’s legislature instituted civil unions (the bill was signed into law by a Republican governor); with Vermont, it’s one of only two states to have established this legal alter ego for heterosexual marriage. Even before the Massachusetts court ruled, California lawmakers had moved to beef up their own domestic-partnership law to grant nearly all the entitlements of a marriage license; then, last September, they passed a bill creating actual gay marriage—which Governor Arnold Schwarzenegger vetoed. Also last year, Maryland lawmakers passed a bill creating a formal statewide registry of “life partners” to facilitate medical decision-making. Republican Governor Robert Ehrlich vetoed it but took enough political heat for doing so that he came back in the following legislative session with a watered-down proposal of his own.

Then there’s Massachusetts itself. After the state high court’s ruling, the backlash seemed all but certain to provoke a state constitutional amendment to either outlaw gay marriage entirely or institute a “civil unions yes, marriage no” compromise. But then gay couples began marrying, the world didn’t end, and the political momentum shifted. In September 2005, the legislature decisively rejected an initiative that would have put a constitutional amendment on the ballot. Using a different procedure, gay-marriage foes may get one on anyway in 2008, but they may not—and even if they do, they may not win. The democratic politics of Massachusetts are proving far less hostile to gay marriage than the initial reaction to the court decision suggested.

It’s perhaps too early to call it a trend, but these signs of movement toward gay marriage suggest a more complicated dynamic than a simple confrontation between liberal judges and more traditional, conservative voters. Through a combination of litigation and legislation, we may well see marriage law liberalize dramatically in the bluest of the blue states, even as their red and purple counterparts move to constitutionally establish marriage as exclusively heterosexual. The result will be a dramatic divide in the legal structures that govern marriage—a gulf that will challenge federalism as few issues have in recent American history.

Which states seem likely to recognize gay marriage?

Currently, advocates are pursuing litigation in Washington—where a state Supreme Court decision could come down any time—and in California, Connecticut, Iowa, Maryland, New Jersey, and New York. In some of these states, gay-marriage proponents are simultaneously pursuing legislative change. We can also expect further pushes for reform in states like Maine, Hawaii, and Vermont. The interactions between the legislative efforts and the litigation are complicated—the threat of successful litigation can spur legislatures to reform marriage law themselves, but successful litigation can also trigger a backlash. So the likelihood of change varies from state to state, as does the specific mechanism. But I think it is reasonable to expect that ten years from now—perhaps much sooner—most of these states will have either formalized same-sex marriage or established institutions very much like it.