Republican Sen. Mark Kirk backs gay marriage: How big a deal?

Sen. Mark Kirk became the second Republican senator in as many months to declare his support for gay marriage. But he's a moderate from a solidly blue state.

Illinois Sen. Mark Kirk is now the second Republican in the US Senate to support gay marriage. Senator Kirk made the announcement via his Senate blog Tuesday, saying “life comes down to who you love and who loves you back – government has no place in the middle.”

Kirk joins Sen. Rob Portman of Ohio, who took a similar position last month. There are now 50 US senators who support gay marriage, a number that includes 46 Democrats and two independents.

Like Senator Portman, whose gay son prompted his change in stance on the issue, Kirk framed his reversal on his personal life. He suggested his return to the Senate after a year absence following a major stroke played a role in his decision.

“When I climbed the Capitol steps in January, I promised myself that I would return to the Senate with an open mind and greater respect for others.… Our time on this earth is limited, I know that better than most,” he wrote.

While Kirk's switch carries some symbolic weight, far more significant would be a Republican senator in a red state openly supporting gay marriage. Last week, Sen. Lisa Murkowski (R) of Alaska told a local media outlet that her views on gay marriage are “evolving” but would not commit further. Only two Republicans in the US House, Reps. Ileana Ros-Lehtinen of Florida and Richard Hanna of New York, are on record with their support.

Kirk is on record as a moderate on gay rights, which reflects the fact that he represents a solidly blue state and won the Senate seat formerly held by President Obama.

Kirk lives in Highland Park, a Chicago suburb that swings moderate to liberal on social issues. He has supported civil unions, opposed a constitutional amendment to ban gay marriage, and, in November 2010, was one of eight Republican senators who voted to repeal "don't ask, don't tell," the policy that barred gays from serving in the military.

During his 2010 Senate race, he opposed gay marriage and backed the federal Defense of Marriage Act (DOMA) – which defines marriage as between a man and a woman – though he added: “I also don't think we should have a federal takeover of all marriage law in the United States. I think the federal government is already trying to take over too much,” he said in an October debate that year.

The news from Kirk comes at a time when gay marriage is being contested both at the state and federal levels. Last week, the US Supreme Court heard oral arguments in a case challenging the constitutionality of DOMA. In February, the Illinois Senate passed a measure supporting gay marriage, and media reports say that a small group of House Republicans is expected to add their support.