Not since Gallup started tracking the issue in 1996 has a majority of Americans supported the right of same-sex couples to legally marry — but, according to a poll released today, 53 percent of Americans now say they do.

Just 45 percent of Americans expressed opposition to legal same-sex marriage — also the lowest level of opposition in the history of the poll. The results came from the May 5-8 Gallup Values and Beliefs poll.

Last year, the results were almost exactly the inverse: 53 percent of Americans did not think same-sex marriage should be recognized by the law as valid, while just 44 percent thought it should be recognized as valid. The nine-point increase in support for same-sex marriage is the largest year-to-year shift yet, according to the poll summary.

Go back even further and the contrast is even clearer: In 1996, 68 percent opposed gay marriage and just 27 percent approved it.

More supportive views among younger Americans and the ever-evolving views of Democrats and Independents drove the shift, as Republicans’ views did not change. Nearly 70 percent of Democrats now support same-sex marriage, up from 56 percent last year, while independent support increased by 10 points from 49 percent to 59 percent.

My thoughts: First of all, while unprecedented for Gallup, this cannot come wholly as a surprise. Don’t forget an ABC poll earlier this year already found a majority of Americans support gay marriage. Activism is effective — and on this issue, we’ve seen plenty of it. Parades, protests, petitions, pledges, propositions, etc., etc., etc.

Within the past year, as the poll itself points out, Congress passed and President Barack Obama signed a repeal of “Don’t Ask, Don’t Tell,” allowing gay and lesbian members of the military to openly reveal their sexual orientation for the first time. The Department of Justice officially decided to stop defending the Defense of Marriage Act. President Obama’s official switch can’t be far behind: He says his views, too, are “evolving” on the issue.

But secondly, conservatives and libertarians alike should consider the potential implications of this poll with thoughtful concern. Edward Feser, associate professor of philosophy at Pasadena City College, says it better than I ever could in his essay “What Libertarianism Isn’t.” This excerpt is long, but well-worth the read (as is the full paper, which is some 10 pages):

[W]here traditional moral scruples are concerned, the Hayekian libertarian ought to regard change with as much caution as he would changes to the institutions of property and contract. Nor is it hard to see why this is so, not just at the level of abstract theory, but at the level of the everyday social and political reality. The family, as we’ve said, is one of the main barriers standing between the individual and the state, for it (rather than the state) is the primary focus of a person’s sense of allegiance to something beyond himself, and is also the arena within which a person learns (or should learn) how to become a responsible and self-supporting citizen of the community. When the family is absent in the life of the individual, the state — especially if such other “intermediate institutions” as the church are themselves weakened — tends inevitably to fill the void. Hence the tendency of single mothers, seeking in government assistance a surrogate to absent husbands and fathers, to be among the Democratic Party’s most loyal voters; hence the listlessness and waywardness of so many of the children of those mothers, giving rise to further social problems to which the same party is only too willing to offer state-empowering “solutions”; and hence the self-accelerating cycle of moral decline leading to state intervention leading to dependency and further moral decline which has characterized social life in the Western world since at least the sixties. For such reasons, maintaining the stability and health of the family must be a chief concern of libertarians as much as of conservatives.

But a libertine ethos is manifestly incompatible with this concern. For the health of the family depends essentially on the willingness of its members to make sacrifices for its sake, and this means, first and foremost, a subordination of the fulfillment of the parents’ immediate desires to the long-term project of building a stable and loving home for their children. That, of course, calls for marriage, and also for precisely the opposite of the frivolous attitude with which marriage is currently treated in the Western world — as primarily a vehicle for “personal fulfillment” which one can enter and exit at will. A society in which the family is strong is thus a society in which adultery is abominated (even in presidents) and in which divorce, even if occasionally permitted, is frowned upon. Since so “stringent” (to the modern mind, anyway) a conception of marriage might make it less likely that men especially will enter into it if (as our mothers used to say) they can “get the milk for free without buying the cow,” it follows that taboos against pre-marital sexual relations, pornography, etc., will be almost as strong as the taboos against adultery and divorce in a society in which the family is taken seriously.

In the end, regardless of what happens in the legal battle, gay marriage will always remain a question of morality in the etymological sense — a question of particular behaviors and of how we interpret the significance of those behaviors. The case against gay marriage will remain extremely hard to make as long as we interpret the meaning of sex as no more than pleasure, self-fulfillment and a sense of unity between romantic partners and of marriage as no more than increased social status, legal benefits and a barrier to being alone.