South Dakota Sen. Tim Johnson says he now supports legalizing gay marriage.
The Democrat released a statement Monday saying that after lengthy consideration, his views on the issue have evolved. He notes that such a law would apply only to governments and wouldn't require "any religious denomination to alter any of its tenets."
In 2005 and 2006, Johnson said he didn't support gay marriage but also didn't believe a constitutional amendment banning gay marriage in the U.S. was needed.
Johnson recently announced that he wouldn't seek re-election next year.
His announcement leaves just three Senate Democrats who oppose gay marriage: Mary Landrieu of Louisiana, Mark Pryor of Arkansas and Joe Manchin of West Virginia. Landrieu and Pryor are up for re-election next year in their Republican-leaning states.