Casey, a Pennsylvania Democrat, said Monday he made the shift after reviewing the legal, public policy and civil rights questions involved.
“After much deliberation and after reviewing the legal, public policy and civil-rights questions presented, I support marriage equality for same-sex couples and believe that DOMA should be repealed,” Casey said in a statement released to the Philadelphia Gay News on Monday.
Casey referenced one lesbian woman from Southeastern Pennsylvania who contacted him, detailing the financial and societal setbacks she, her partner and their children have faced from being denied the right to marry.
“As a senator and as a citizen, I can no longer in good conscience take a position that denies her and her family the full measure of equality and respect,” Casey said.
In November, as he successfully sought a second term, Casey said he favored same-sex civil unions but did not take a position on same-sex marriage. He previously has voted to let gays and lesbians serve openly in the military and to repeal the “don’t ask, don’t tell” policy.
Casey, a Roman Catholic from Scranton, Pa., opposes abortion rights, except in cases of rape, incest or when the life of the mother is in danger.
The president of the Pennsylvania Family Institute, which opposes gay marriage, said Casey acted in response to pressure from special interests.
“There were many Pennsylvanians, Democrats and Republicans alike, who voted for Senator Casey because he respected many of the social conservative values of Pennsylvania – on the life issue as well as the marriage issue,” president Michael Geer said. “I think many supporters of Senator Casey hoped for more from him and today are sadly disappointed.”
On Friday, NBC News reported that progressive organizations and their supporters have bombarded Casey’s office with 10,000 calls and emails urging him to support same-sex marriage.
A Franklin and Marshall poll found earlier this year that 52 percent of registered voters in Pennsylvania supported same-sex marriage and 41 percent opposed it, a swing of 19 percentage points since 2006.
Casey is the 48th U.S. senator to throw his support behind same-sex marriage. Forty-four other Democrats, two independents who caucus with Democrats and one Republican, Ohio Sen. Rob Portman, had previously announced their support.
With Casey’s announcement, there remains eight Senate Democrats who still publicly oppose same-sex marriage; they are: Bill Nelson of Florida, Joe Manchin of West Virginia, Heidi Heitkamp of North Dakota, Tom Carper of Delaware, Mary Landrieu of Louisiana, Tim Johnson of South Dakota, Mark Pryor of Arkansas, and Joe Donnelly of Indiana.
No other Republicans in the Senate besides Portman publicly supports gay marriage.