For most Democrats -- especially those in and around Chicago -- same-sex marriage is a winning political issue with core voters.
It's a lot tricker for Republicans. A majority of conservatives are opposed to legal same-sex marriage, but in a Democratic-leaning state like Illinois, Republicans need to win votes from independents, too.
State Treasurer Dan Rutherford, for example, opposed the marriage legislation. That's after his vote in favor of civil unions back when he was a state senator.
Now campaigning for his party's nomination for governor, Rutherford was asked whether he would work to repeal same-sex marriage.
"No. It's going to be law. You know, one of my competitors in the primary is going to pursue to repeal civil unions, too. It's going to be the law."
Rutherford was referring to state Sen. Kirk Dillard of Hinsdale. Dillard had a prominent speaking role at an anti-same-sex marriage rally last month in the Statehouse.
Democratic Gov. Pat Quinn is going the opposite direction. He's scheduled a public signing of the marriage bill next week at a venue that can accommodate thousands of spectators.