A coalition is seeking to raise support for the Employment Non-Discrimination Act. (Seth Wenig/AP)

A coalition of civil rights groups is launching a $2 million campaign aimed at mobilizing support for the Employment Non-Discrimination Act, which has languished on Capitol Hill for nearly two decades.

The coalition, called Americans for Workplace Opportunity, is targeting 13 senators in 11 states in hopes of replicating the strategy gay marriage advocates have used to push successful state ballot initiatives.

The effort includes gay rights groups such as the Human Rights Campaign and the GOP-leaning American Unity Fund, as well as the Leadership Conference on Civil and Human Rights and the Service Employees International Union.

Campaign manager Matthew McTighe, who led last year’s successful gay marriage ballot initiative in Maine, said the gay rights movement is “finally taking this model we know works and applying it to a new issue.”

Wade Henderson, president of the Leadership Conference on Civil and Human Rights, said groups like his had also learned key lessons from its efforts on behalf of immigration reform.

“Since Congress last debated this, our field capacity has grown more sophisticated and our targeting and the range of voices speaking out have changed the game,” Henderson said. “The same is possible for ENDA.”

Twenty-one states and the District of Columbia ban employment discrimination on the basis of sexual orientation, and 17 of those states and the District extend that protection to gender identity. Such policies have also become common in major companies: 88 percent of Fortune 500 include protections for gay, lesbian and bisexual employees, and more than half have safeguards for transgender employees.

Until recently the push for workplace protections has been overshadowed by the battle over gay marriage. But on July 10 the Senate Health, Education, Labor and Pensions Committee approved anti-discrimination bill by a bipartisan vote of 15 to 7, providing fresh momentum to the initiative.

The coalition, which also includes the American Civil Liberties Union, American Federation of Teachers, National Center for Transgender Equality and National Gay & Lesbian Task Force, will focus on senators in Arizona, Arkansas, Florida, Idaho, Indiana, Nevada, New Hampshire, New Jersey, Ohio, Pennsylvania, and West Virginia. With the exception of Democrats Mark Pryor (Ark.), Bill Nelson (Fla.) and Joe Manchin III (W.Va.), all the targeted senators are Republican.

HRC President Chad Griffin said he was optimistic the campaign, which will also include business leaders, would be able to persuade conservative and centrist lawmakers to support the law.

“Everyone should have the opportunity to get and keep a job and provide for themselves and their family,” Griffin said. “It’s a conservative principle and value, and it’s something the vast majority of voters agree with.”

According to a Public Religion Research Institute poll released in May, respondents favored a law protecting gays and lesbians from employment discrimination by a margin of 73 percent to 22 percent. A 2003 Gallup poll found 88 percent of respondents believed gays should have equal rights in the workplace.

Critics of the measure, including Traditional Values Coalition President Andrea Lafferty, said the fact that it provides protection for transgender Americans will make it hard for even some Democratic senators to accept.

Within the gay movement, Lafferty argued, transgender people “are kind of like the crazy aunt at Thanksgiving. They put up with the crazy aunt at Thanksgiving, but they don’t want to be seen with her in public.”

Before the Senate panel voted on the bill this month, supporters organized a postcard-writing campaign aimed at Sen. Lisa Murkowski (R-Alaska), who attributed her yes vote in committee to what she heard from her constituents.

“Like most Alaskans, Senator Murkowski is a strong believer that individuals should be judged on whether they can do the job, not their sexual orientation,” spokesman Matthew Felling wrote in an e-mail.

Even if the measure can pass the Senate, however, it will have a more difficult time in the GOP-controlled House.

Griffin, however, said the first obstacle is the Senate. “The hurdle we face immediately is getting the 60 votes in the Senate,” he said. “That’s where our focus and attention is now.”