Democratic U.S. Sen. Bob Casey announced Monday that he favors gay marriage, the latest of several lawmakers to change positions on the issue now before the U.S. Supreme Court.
Casey said he made the shift after reviewing the legal, public policy and civil rights questions involved and letters from Pennsylvania families.
"If two people of the same sex fall in love and want to marry, why would our government stand in the way?" Casey said. "At a time when many Americans lament a lack of commitment in our society between married men and women, why would we want less commitment and fewer strong marriages?"
In November, as Casey successfully sought a second term, he said he favored same-sex civil unions but did not take a position on same-sex marriage. He previously voted to let gays and lesbians serve openly in the military and to repeal the "don't ask, don't tell" policy.
"Elected public officials have an abiding obligation to refrain from demonizing and dividing people for partisan or political gain," Casey said. "Rather, Democrats and Republicans should come together and find areas of agreement to do what's best for the country, including lesbian and gay Americans."
Last week the U.S. Supreme Court heard oral arguments in a pair of cases that could dramatically alter the legal landscape for gay marriage.
One of the cases involves the Defense of Marriage of Act, which prevents legally married gay couples from receiving federal benefits available to others. Casey said he now wants to repeal the law, signed by President Bill Clinton in 1996.
The executive director of Equality Pennsylvania, a political advocacy group for gays, lesbians, bisexuals and transgender people, said his members logged about 10,000 calls to Casey in recent weeks to urge him to make such an announcement.
"I hope what it means for where the state is going is that people are truly starting to use the issue of marriage to understand why marriage equality is important but also in general how we treat gay citizens in Pennsylvania," executive director Ted Martin said.
Casey's announcement, Martin said, gives elected officials "the ability to look at these issues and understand you can come to a conclusion after thinking about them."
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."
Casey, a Roman Catholic from Scranton, opposes abortion rights except in cases of rape, incest or when the life of the mother is in danger.
Several other Democratic senators who, like Casey, represent swing states, have recently made similar announcements.
Sen. Rob Portman, a Republican from Ohio, announced his support for gay marriage in states that choose to allow it, saying his stance began to change in 2011, when his college-age son told him he was gay.