What I think Chait misses, though, is the extent to which Rob Portman's intellectual and moral mediocrity points to an amazing strategic victory by the gay rights movement. As Chait says, Portman's reversal on this issue appears to boil down to pure selfishness. But...there are many issues where selfishness, no matter how pure, does not translate into political action. As just one example, there is, and has long been, a great deal of evidence that women are routinely given Cesareans for no medical purpose. Yet, while there are many mothers who are needlessly subjected to this major abdominal surgery, those mothers and their loved ones do not, for the most part, become advocates for laws legalizing midwifery, or for changes in birth practices. Even though these women have a personal experience of policy failure and injustice, that experience does not translate into political action, because they simply do not see those personal experiences in political terms.

Portman, on the other hand, does see his personal experience with gay issues in political terms. That's not because he's especially sensitive or thoughtful—there is no reason to think he is either. Rather, it's because gay rights advocates have been so successful in linking the personal and the political together that even the most unreflective career pol can't help but connect them.

In large part, gay activists have done this precisely by focusing on marriage. As Michael J. Klarman explained in his recent book, From the Closet to the Altar, there was much tension in the gay rights movement over the strategic decision to focus on same-sex marriage. Many activists wanted instead to concentrate on anti-discrimination laws, or even on civil unions. The focus on same-sex marriage—a focus determined by individuals on the ground as much as by national organizations or activists—resulted in many setbacks and defeats, and energized Republicans for years. Anti-gay marriage ballot measures may well have given Bush the state of Ohio and the presidency in 2004.

But while there were downsides, the focus on gay marriage has also had huge successes—and one of those successes is the way in which it has so forcefully connected personal and family ties to politics. Marriage—he public acknowledgement of personal commitment—has become the symbol for gay rights. And as a result, Rob Portman cannot look at his gay son without seeing that that his gay son's family—Portman's family—is a political issue that requires a political stance.

Portman's op-ed makes him sound like someone who, faced with a moral dilemma, has muddled through as best he can with the least thought and effort possible. The fact is, though, that most of us, most of the time, are more like Rob Portman than we are like, say, Mildred Loving, the woman whose Supreme Court case overturned the laws against interracial marriage. The marriage equality movement, like any moral movement, has been built by activists with great struggle and courage. But it's success is measured by the fact that it has framed the issues in question such that even the selfish and small-minded can, given a little push by their families, make the right choices. Portman is not an inspiring figure. But there is something inspiring in realizing that the movement has reached a point where even someone like him finds it easier to make the right choice than the wrong one.