Illinois Will Pass Marriage Equality Bill, Sponsor Says

May could become an even more spectacular month for marriage equality: The sponsor of the Illinois bill predicts it will pass by the month's end, which is also the end of the legislative session.

Rep. Greg Harris, the chief sponsor, said he will "absolutely" call a vote on the marriage equality bill by May 31, and "it's going to win," Chicago's Windy City Times reports. Harris has previously said he would not bring the measure to a vote in the House of Representatives unless he was sure there was enough support to pass it. The state Senate approved it Valentine's Day, and Gov. Pat Quinn has vowed to sign it.

The bill picked up an endorsement today from former president Bill Clinton, who issued a statement invoking another president. "Since the days of Abraham Lincoln, Illinois has stood for the proposition that all citizens should be treated equally under the law," President Clinton said in Tuesday's statement. "Lincoln himself came to Springfield in search of opportunity, and he dedicated his life to securing equal opportunity for all citizens. I believe that for Illinois and for our nation as a whole, in the 21st century that must include marriage equality."

Several other supporters of the bill have predicted it would pass by May 31, according to Windy City Times. If this happens, Illinois will join three other states -- Rhode Island, Delaware, and Minnesota -- that have approved marriage equality in the past few weeks. Twelve states plus the District of Columbia offer marriage rights to same-sex couples.