Beyond the efforts taking place in Congress, an additional anti-gay marriage effort is being made in D.C. Superior Court.
A group called Stand4MarriageDC wants a ballot measure which says that "only marriage between man and woman" should be "valid or recognized" in the city.
Last month, the D.C. Board of Elections and Ethics ruled that allowing residents to vote on a gay marriage ban would violate Washington's 1977 Human Rights Act, which prohibits discrimination.
The Stand4MarriageDC group is now suing in Superior Court on the theory that if the Council has the right to change the law in order to allow same-sex couples to marry, then the people have the right to make laws on the same subject.
"I think proponents of same-sex marriage are afraid of having a vote because traditional marriage typically wins," said Chaffetz.
The architect of Tuesday's gay marriage legislation countered by saying that questions about minority rights should not be left to votes of the people. To make his argument, D.C. City Councilmember David Catania noted that the district had a referendum in 1865 in which only 36 of the city's residents voted to extend the franchise to African-American males.
"It isn't that I'm fearful of losing," Catania told ABC News. "I think the process is diminishing. I think that putting the rights of minorities on the ballot and allowing the forces of intolerance to spend an unlimited amount to demonize and marginalize a population is ... unsavory."
The groundwork for today's vote was laid in May of this year when the D.C. Council voted to recognize gay marriages performed in other states.
Catania says that while the May vote may seem incremental, it was in fact the bigger leap.
"We're fighting about whether or not couples have to get on a plane to get married--not whether or not they can," said Catania. "It's about where the marriage should take place--not whether or not it is the lawful equivalent of a heterosexual marriage. That happened over the summer."
ABC News' Elizabeth Gorman contributed to this report.