44% say gay and lesbian couples should be allowed to get married. Just two years ago, only 34% thought so.
Jason Pierceson, a political science professor at UIS, says there are a couple of reasons for the spike, one being the civil union law passed last year.
"Sometimes law can shape opinion, so if there's a law that says we're going to protect same sex couples and it's written into law that they're deserving of respect and integrity and protection I think that has helped," he said.
The poll was conducted by Southern Illinois University's Paul Simon Public Policy Institute.