The Williams Institute provided marriage equality crusaders their best lobbying tool.

Equality Illinois Public Policy Director Randy Hannig said the report will come in handy as the Equality Illinois bipartisan team discusses the bill with legislators and Illinois Gov. Patrick Quinn’s administration.

"This report affirms that there are no reasons in logic or law why thousands of Illinois couples and their children should be deprived of the same legal protections and social and community support that other families enjoy," Equality Illinois CEO Bernard Cherkasov said.

The act guarantees marriage equality under state law. Illinois currently allows gay and straight couples to enter civil unions.

Same-sex weddings, over three years, would pump between $39 and $72 million into the state’s struggling economy, the Williams Institute at the UCLA School of Law noted. That’s not counting an estimated $4 to $8 million in state taxes.

"When the state is struggling to raise every dollar possible, it is good to point to marriage equality as something that costs taxpayers nothing, serves to improve the state's business environment and brings in millions of dollars in revenue," Hannig said in a press release.

Those nuptials would bring long-lasting benefits to more than 23,000 couples. Nearly 4,000 of those couples are raising about 8,000 children, according to the 2010 U.S. Census. About 110,000 couples are raising more than 200,000 children nationwide.

Other Williams Institute research reveals 50,000 gay and lesbian couples are in legally-recognized marriages.

Photo: gregharris.org