President Obama’s announcement that he supports same-sex marriage may have had an immediate impact on political discourse, but the same can’t be said of its implications for constitutional jurisprudence. For those hoping for a forthright defense of constitutional protections for gay rights, Obama’s announcement seemed to raise more questions than it settled.

Commentators were right to point out that Obama’s announced position—that he supports gay marriage, but every state should decide on the matter for itself—is inconsistent with the position his administration took last year in opposing the Defense of Marriage Act. Indeed, the Department of Justice announced that “strict scrutiny” of anti-marriage laws reveals them to be motivated by anti-gay animus, and thus unconstitutional; in other words, Attorney General Eric Holder suggested this was precisely an issue that states aren’t free to decide on their own.

In contrast with such bold declarations of principle, Obama famously cited the personal nature of his “evolution:” It was motivated, he said, by conversations he had with wife and his daughters about friends who have gay parents. But it would be hasty, not to mention cynical, to conclude that Obama invoked his family to avoid having to discuss constitutional protections for same-sex marriage. Rather, those invocations may have been a shrewd suggestion of how such protections can best be achieved.

PSYCHOLOGICAL RESEARCH HAS shown that the reasons Obama cited as having changed his mind—in particular, conversations with his wife and daughters about their gay friends—is precisely what has persuaded a bare majority of Americans to embrace gay marriage in recent years. According to Gregory Herek, a psychologist at the University of California at Davis who is a leading authority on how people change their minds on matters involving gay and lesbian discrimination, Obama’s personal evolution was entirely typical. Simply having a lesbian or gay friend isn’t enough to change people’s minds, Herek says. Instead, the decisive factor is whether someone has had a personal conversation about what it’s like to be gay and how it influences a person’s life.

In a 2005 study, however, Herek found that a significant majority of gay men and lesbians hadn’t had those kinds of conversations with straight people in the past year, even though they were out of the closet. This is where wives and daughters come in. Herek argues that in the last several years public opinion has been transformed by heterosexual women like Michele Obama taking the role of “ally” for gays and lesbians—initiating conversations with their male relatives about marriage equality, and communicating the idea that they won’t tolerate prejudice.