Mark Kirk Backs Gay Marriage

Sen. Mark Kirk (R-Ill.) announced his support for same-sex marriage Tuesday, becoming the second Republican senator to do so after his colleague Sen. Rob Portman (R-Ohio) embraced marriage equality last month .

"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," Kirk said in a statement posted to his blog .

"Same-sex couples should have the right to civil marriage," he continued. "Our time on this earth is limited, I know that better than most. Life comes down to who you love and who loves you back -- government has no place in the middle."

A flurry of lawmakers have weighed in on gay marriage in the wake of the Supreme Court's consideration of landmark cases on the federal Defense of Marriage Act and California's Proposition 8. But the majority of endorsements have come from Senate Democrats , who only have seven remaining holdouts in their caucus.

Kirk is the 50th senator to back gay marriage. He and Portman are the only Republican senators to express their support, though Sen. Lisa Murkowski (R-Alaska) recently said her position was evolving. Portman said he reached his decision after his son came out as gay.

As a House member, Kirk voted against the repeal of Don't Ask, Don't Tell two times . He also voted against it while in the Senate as a committee member , but then backed repeal in the final Senate vote .

Clarification: This story has been updated with additional information about Kirk's voting record with regard to DADT.