It is remarkable how fast the issue of same-sex marriage has moved the American public. Of course, some long-time proponents will argue the opposite, that it has taken far too long for it to gain acceptance. And they say that there is no shortage of efforts around the country to block or overturn the practice.

But there is no question that since Vice President Biden first announced his support for the issue last May — jumping the gun on President Obama, whose position on the issue was said to still be "evolving" — things have changed rapidly. Almost immediately, and far more significant, was Obama's declaration he felt the same. After that came dramatic shifting in public opinion, where for the first time ever, polls show that more people support gay marriage than oppose it. It became a cause to be celebrated at the Democratic National Convention last summer. Voters in three states, after an unbroken string of defeats, chose to legalize gay marriage in November. And it got considerable attention at Obama's inauguration in January, where he said, "Our journey is not complete until our gay brothers and sisters are treated like anyone else under the law, for if we are truly created equal, then surely the love we commit to one another must be equal as well."...

But if we're talking about politicians who have had a change of heart, add former President Bill Clinton to the list. The issue here is the 1996 Defense of Marriage Act (known by its acronym DOMA), which defines marriage as being between a man and a woman and which would deny federal rights to same-sex spouses. (Portman, then a House member, was a sponsor of the Act.) Recently Clinton penned an op-ed in the Washington Post saying it should be overturned. Clinton, of course, was president when he signed DOMA into law on Sept. 21, 1996. The issue of overturning it comes before the U.S. Supreme Court on March 27, when the constitutionality of California's Proposition 8 — a 2008 anti-gay marriage initiative passed by the voters — will be decided....