His personal "evolution" complete, President Obama this week declared: "I think same-sex couples should be able to get married." He thus ended years of unnecessary fence-sitting and gave hope to thousands of gay and lesbian couples that one day they will have the same rights and legal protections as heterosexual couples.
The battle for legal recognition of civil marriage for same-sex partners will not end with Mr. Obama's change of heart. But simple demographics suggest that there is little doubt about the eventual outcome of this often-bitter debate.
Opposition to gay marriage is strong among evangelicals, the Catholic Church hierarchy, and African-Americans. They have racked up impressive short-term victories. This week, North Carolina became the 30th state to ban gay marriage.
In 2004, Ohio voters strongly approved a state constitutional amendment that defines marriage as between a man and a woman. But the pendulum has begun to swing the other way: The Ohio Freedom to Marry Coalition hopes to gather enough signatures to put an amendment on the ballot next year that would give legal status to gay marriages.
While Americans are evenly split on this issue, a growing majority of young people support marriage equality. Time is on their side.
President Obama's statement has symbolic value for gay couples because, as New York Mayor Michael Bloomberg noted, every time a president has weighed in on an expansion of rights, it eventually became law. His remarks also offer strong national leadership.
Civil marriage is a basic personal right that should not be left up to the states. There is a powerful argument that gay marriage, like interracial marriage in the 1960s, merits constitutional protection.
North Carolina's ban, which encompasses gay marriages and civil unions, threatens legal unmarried heterosexual couples as well. Insurance companies may be able to deny coverage to their children, and they may not be protected by domestic violence laws. That's wrong.
President Obama fudged for a long time on the issue. He told ABC he "was sensitive to the fact that, for a lot of people, the word 'marriage' was something that evokes very powerful traditions, religious beliefs, and so forth."
The President also may have been loath to give Mitt Romney, his likely Republican opponent in November, a hot-button issue. Mr. Romney supports a constitutional amendment that would prohibit same-sex marriage.
The inability to separate marriage's legal status from its religious significance remains a sticking point for many Americans. Yet the presidential election is not likely to turn on divisive social issues. The economy is still most important to voters, polls suggest.
Mr. Obama took a stand when he didn't have to on an issue that divides many people. But defending the rights of Americans is never the wrong thing to do.