CHICAGO Building on the momentum of President Barack Obamas recent support of gay marriage, two major civil rights groups in his home state filed lawsuits Wednesday in hopes of legalizing same-sex marriage in Illinois.

The two lawsuits brought by the ACLU of Illinois and the New York-based Lambda Legal represent 25 couples statewide. Both challenge a state law that defines marriage as between a man and woman, arguing that the Illinois Constitution guarantees the right for same-sex couples to marry under due process and equality clauses.

Its time for Illinois to recognize the love and commitment of these couples, said John Knight, director of the Lesbian, Gay, Bisexual, Transgender Project of the ACLU of Illinois. Weve waited long enough.

Knight said Obamas comments, as well as Gov. Pat Quinns backing of gay marriage earlier this month and nationwide polls showing increasing public support for same-sex marriage set the stage.

The filings come a year after Illinois enacted civil unions, but many couples in the lawsuits said civil unions made them feel like second-class citizens.

Lambda Legals lawsuit, which has 16 couples, includes Chicagoans Patrick Bova and Jim Darby. Theyve been together for 48 years and hope to marry by their 50th anniversary. They entered into a civil union last year, but said they want their relationship to be recognized in the same way as their heterosexual friends.

I have bought so many toasters for so many weddings, Darby said Wednesday at a news conference. I want someone to buy me a toaster.

The 25 couples in both lawsuits tried to apply for marriage licenses in Cook County, but were denied.

Its unclear how Illinois will handle the cases legal process, but attorneys with the advocacy groups are ready to take them to the state Supreme Court. The defendant named in the case, Cook County Clerk David Orr, is personally in favor of gay marriage. Several messages left for Cook County States Attorney Anita Alvarez, who would represent Orr, were not immediately returned Wednesday.

A spokeswoman said Orr was out of the country and had not seen the lawsuit, but issued a statement on his behalf.

The time is long past due for the State of Illinois to allow County Clerks to issue marriage licenses to couples who want to make that commitment, the statement said. I hope this lawsuit clears the last hurdle to achieving equal marriage rights for all.

The District of Columbia and six states Connecticut, Iowa, Massachusetts, New Hampshire, New York and Vermont have legalized gay marriage. Courts decided for gay marriage in Massachusetts, Connecticut and Iowa. A lawsuit, filed by Lambda Legal, challenging an Iowa law that barred gay marriage prompted the Iowa Supreme Court to legalize it in 2009.

Legislation to eliminate language that prohibits gay marriage is pending in Illinois, but a vote isnt expected before the session is scheduled to end this week.

Illinois civil unions give same-sex couples some, but not all, of the same legal rights and protections as marriage, such as the power to decide medical treatment for a partner and to inherit a partners property.