The push for gay marriage came just two years after Illinois legalized civil unions for same-sex couples and reflects shifting attitudes in favor of same-sex marriage.



Under the latest measure, the definition of marriage would be changed in state law from an act between a man and a woman to one between two people. Civil unions could be converted to marriages within a year of the law going onto the books.



The legislation would not require religious organizations to perform a marriage of gay couples, and church officials would not be forced to allow their facilities to be used by gay couples seeking to marry.



While advocates have brought forth a lengthy line-up of religious leaders who have endorsed gay marriage, Catholics and conservative African American church groups have provided fierce opposition. They argue same-sex marriage violates the basic tenets of the Bible, which call for marriage to be only between a man and a woman.



Advocates argue a prohibition on gay marriage goes against American values of equality and fairness.



They gathered ahead of the debate Thursday afternoon to demand a vote, detailing hurdles same-sex couples face without full legal recognition of their relationship.



Mercedes Santos and Theresa Volpe of West Rogers Park detailed how hospital officials would not let them both in the room when their now 5-year-old son was hospitalized for kidney failure because "there couldn't be two moms."



"My son was dying and the last thing I needed to do was sit and try to explain to them who I was," Volpe said. "We feel very strongly about the message that's being sent today to our family. ... It's about equality and our family is just as equal as any other family that is allowed to have marriage."