Sponsors of the Respect for Marriage Act said Tuesday the bill has exceeded 100 co-sponsors.

Representatives Jerrold Nadler (D-NY), Tammy Baldwin (D-WI) and Jared Polis (D-CO) introduced the bill that would repeal the federal Defense of Marriage Act (DOMA) at a Washington outdoor press conference in September.

DOMA was signed into law by President Bill Clinton 13 years ago. The law defines marriage as a heterosexual union for federal agencies and allows states to ignore gay marriages performed in other states. Under DOMA legally married gay and lesbian couples cannot access federal benefits, including Social Security and pensions.

“Only weeks following the introduction of the Respect for Marriage Act, we have the support of over 100 members of Congress for this historic bill,” Nadler said in a statement.

“This progress demonstrates in no uncertain terms that support for our legislation is growing every day and that there is broad support from across the country to repeal DOMA now. Gay and lesbian Americans simply must not be the target of discrimination under federal law,” he added.

DOMA has been under intense fire since President Obama's Department of Justice defended the law in a California lawsuit that aimed to overturn the statute. That suit has since been dismissed on a technicality, but petitioners have vowed to refile their challenge. In filing their final brief, administration lawyers greatly reined in the anti-gay sentiment of their arguments.

Other challenges to the law continue as well, including two suits filed in Massachusetts and one in California. California petitioners are hoping a federal judge will agree that Proposition 8, the voter-approved referendum that bans gay marriage in the state, is unconstitutional, while Massachusetts petitioners are only challenging DOMA's provisions that block gay and lesbian couples from accessing federal benefits. All three suits are likely to reach the Supreme Court.

In his most recent address to the gay community, Obama modestly broached the subject.

“I believe strongly in stopping laws designed to take rights away and passing laws that extend equal rights to gay couples,” Obama told 3,000 gay activists at an October 10 Human Rights Campaign (HRC) fundraiser. “I've required all agencies in the federal government to extend as many federal benefits as possible to LGBT families as the current law allows. And I've called on Congress to repeal the so-called Defense of Marriage Act and to pass the Domestic Partners Benefits and Obligations Act.”

While the bill is gaining traction, the nation's most powerful openly gay elected official, Massachusetts Representative Barney Frank, says passage this year is unlikely.

“It's not anything that's achievable in the near term,” Frank told gay weekly The Washington Blade.

“I think getting [the Employment Non-Discrimination Act], a repeal of 'don't ask, don't tell,' and full domestic partner benefits for federal employees will take up all of what we can do and maybe more in this Congress.”

The bill does not repeal DOMA entirely, states would still be allowed to ignore gay marriages performed outside their borders, but it would recognize marriages even in states where they have been deemed illegal, granting couples 1100 federal benefits in states that disapprove of gay marriage.

“For the purposes of any Federal law in which marital status is a factor, an individual shall be considered married if that individual's marriage is valid in the State where marriage was entered into …,” the bill says.

Frank disagreed with the provision, saying it would “stir up unnecessary opposition.”

“I don't think it's a good idea to rekindle that debate when there's no chance of passage in the near term,” Frank said.