Republican Senator Lisa Murkowski of Alaska has just become the third GOP Senator to support gay marriage, aka “marriage equality.” The other two are Mark Kirk of Illinois and Rob Portman of Ohio.

Portman famously endorsed gay marriage in marriage of this year, while simultaneously announcing that his son was gay. He was the first Republican Senator to come out for gay marriage, and faced significant backlash from party activists for “agreeing with sodomy.”

Kirk came out for marriage equality in April, issuing a succinct and poignant statement of support:

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. Same-sex couples should have the right to civil marriage. 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.

In addition to the 3 Republicans, 49 Senate Democrats and 2 Independent senators (who caucus with the Democrats) also support gay marriage.

The three Democratic Senators who refuse to support gay marriage are Mary Landrieu of Louisiana, Joe Manchin of West Virginia, and Marko Pryor of Arkansas.

The news of Murkowski’s change of heart on gay marriages as the Supreme Court is expected to issue a ruling on two major gay marriage cases, one involving the Defense of Marriage Act (DOMA), and a second concerning Proposition 8. DOMA bans the federal government from providing federal benefits to legally-married gay couples and stops states from having to recognize each other’s same-sex marriages. Prop 8 was passed in California in 2008 in order to repeal the right to marry for gay couples in that state.

The decision on those cases could come as early as 10:00 am Eastern time on Thursday morning.