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Republican Sen. Mark Kirk of Illinois has become the second Republican senator to endorse same sex marriage, tipping the balance of opinion in the Senate.

In a statement released today, Kirk mentions that in his recovery from his stroke last year he promised he would return to the Senate with an "open mind and greater respect for others."

With Sen. Tom Carper's announcement today that he, too, has "evolved" on gay marriage and Vice President Joe Biden as a tie-breaker, this marks the first time that a majority in the U.S. Senate has endorsed same-sex marriage.

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

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Kirk is the second Senate Republican to flip positions on this issue, following Sen. Rob Portman, R-Ohio, and a string of eight Senate Democrats in two weeks.

There are only seven Senate Democrats left who continue to oppose marriage equality in some way.