From the Chicago Tribune:

U.S Sen. Tom Harkin said Friday he's changed his views on gay marriage and would oppose any effort to overturn an Iowa Supreme Court decision last month that legalized same-sex unions.

"We all grow as we get older, we learn things, we become more sensitive to people and people's lives," said Harkin. "The more I've looked at that, I've grown to think differently about how we should live. I guess I've got to the point of live and let live."

Harkin is the senior senator from Iowa—and he voted for the Defense of Marriage Act in 1998, which currently bars any federal recognition of the legal marriages of same-sex couples in Iowa. Obama promised to repeal DOMA during the campaign.