The notable silence by the Republicans on the issue of same-sex marriage during the current election campaign is a sign, if one needed one, of how rapidly sentiment has shifted on this issue. In 2004 opposition to this was very potent and was used to galvanize voters to go to the polls and vote for George W. Bush. Daniel McCarthy argues in The American Conservative that it is one more sign of the retreat of religion in the face of modernity.

The gradual triumph of gay marriage is not merely due to a legal change that began 20 years ago or even to the sexual revolution of a half-century past; rather it is a consequence of a shift in the foundations of Western civilization that has been taking place over centuries—a shift from Christian to liberal foundations.
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As Christianity has lost its power in public life, so too have the forms of marriage and family that it established given way to new configurations shaped by the institutions and ideologies that hold power today—specifically, liberalism and the modern state.

He argues that conservatives should embrace this new reality.

The second consistent position that conservatives can embrace, however reluctantly, would be that of providing full legal equality. This could be seen as a capitulation to liberalism; it could also be seen as an acknowledgement of reality. The trouble with this position is that it doesn’t stop where most conservatives would like it to stop: the logic of legal equality certainly demands that homosexuals be allowed to serve in government, including in the military, and prima facie it demands that they be afforded equal access to the institution of marriage. Conservatives can try to draw the line before that point, but doing so requires making an exception to the principle of legal equality, and exceptions are, by their very nature, more difficult to establish than arguments that go along with general rules.
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Same-sex marriage will not lead to civilizational collapse; the social atomism of which it is a symptom is more likely to do that. But there are tough questions about how nondiscrimination and public-accommodations laws will be applied against religiously affiliated institutions, even if churches themselves are exempt from having to participate in the public status of same-sex marriage. Traditionalists are right to be worried: religious liberty too is treated as an exception to liberalism, one for which powerful arguments must be made and which always faces an uphill battle. But the key problem here may not be whether or not there’s gay marriage, but the reach of non-discrimination and public-accommodations law.

Social conservatives have a hard time tackling those concerns, however, because of the inherited guilt they feel over the retrograde views that many past conservatives held about legal equality for racial minorities.

Even conservative activist Phyllis Schlafly thinks that they are losing this battle and blames (of course) public education.

In England too, the writing is on the wall. An Anglican bishop Nicholas Holtam has said that his church’s opposition to same-sex marriage has been a disaster and “compared bishops opposing marriage reforms to 18th century Christians who believed slavery was “God-given”.” It will be interesting to see who gets nominated to be the next Archbishop of Canterbury, the titular head of the worldwide communion of Anglicans. One of the early leading contenders had been John Sentamu, an ardent opponent of same-sex marriage, but his star seems to have waned recently.

This November there are referenda on same-sex marriage in four states in the US (Maine, Maryland, Minnesota, and Washington) and it will be interesting to see how they play out. Pew surveys show a big swing nationally on this issue, with a 54-37% margin opposing it in 2009 to 48-44% favoring it in 2012, a massive swing of 21 points in just three years. A win in any one of these races will have huge symbolic value because so far the six states and the District of Columbia where same-sex marriage is legal have done so either due to court rulings or actions by the legislature. All referenda have so far failed to pass.

Interestingly, opposition to same-sex marriage is waning even in the black community, where opposition has traditionally been very strong, as can be seen in Maryland.

According to the Sun, “there’s been a dramatic shift in the attitudes of black voters.” The paper found that “more than half of likely black voters favor legalizing same-sex marriage, compared with a quarter who are opposed.” This is huge in a state where black voters are thought to be a quarter of all Maryland voters.

Another sign of the changing times is that major labor unions, who tend to shy away from taking stands on social issues and are not always the most progressive voices on them, are backing same-sex equality.

So the votes in the four states this November will be an interesting bellwether of how far public sentiment has shifted in favor of equal rights for the LGBT community in general and same-sex marriage in particular. While opponents have lost a lot of ground in the last eight years, there is good reason to be cautious. There could be setbacks, as was seen in the surprisingly large margin of 61% to 39% by which a ban on same-sex marriage passed in May in North Carolina.