Linda Royster, right, and Barbara Kinsman wait inside the Staunton City Courthouse to apply for their marriage license on Friday, Feb. 14, 2014, in Staunton, Va. (AP Photo/The Daily News Leader, Katie Currid)

A group supporting same-sex marriage will kick off an advertising campaign in Southern states in hopes of swaying public opinion and the judges who will decide the fate of state bans on gay unions.

Freedom to Marry, the national pro-gay marriage organization based in New York, will announce a new $1 million television ad campaign at a press conference Monday in Atlanta. The campaign, dubbed Southerners for the Freedom to Marry, will highlight prominent politicians and community leaders who back same-sex marriage.

But the ad campaign isn’t trying to win legislative support for same-sex marriage. Every state in the South has passed a constitutional ban on gay marriage, and Republicans dominate all but a small handful of Southern state legislatures.

Instead, the campaign will push to grow public support for same-sex marriage. About two dozen lawsuits challenging bans on gay marriage are pending before state and federal courts in Southern states, and Freedom to Marry hopes that building public support for same-sex marriage can influence those judges’ decisions.

In recent months, judges in Oklahoma, Kentucky and Virginia have struck down state bans on same-sex marriage, though those rulings are stayed until the U.S. Supreme Court weighs in.

“Freedom to Marry’s national strategy has always been to build a critical mass of states and support to create the climate for the Supreme Court to bring the country to national resolution. We don’t have to win within every state, but we have to win enough states,” said Evan Wolfson, president of Freedom to Marry

Atlanta Mayor Kasim Reed will join the group at its Monday press conference. The group will also try to tie same-sex marriage to the civil rights movement, by featuring Rep. John Lewis, the longtime Georgia Democrat who ran the Student Nonviolent Coordinating Committee, in a testimonial.

“I see the right to marriage as a civil rights issue. You cannot have rights for one segment of the population and one group of people and not for everybody,” Lewis says in the video.

Co-chairs will include Sen. Tim Kaine (D-Va.), Reps. James Clyburn (D-S.C.), Ileana Ros-Lehtinen (R-Fla.) and Joaquin Castro (D-Texas), as well as Mark McKinnon, a former senior adviser to George W. Bush and Lance Bass, the ‘N Sync singer.