The United States Senate passed a historic bill yesterday that would ban workplace discrimination against gay and transgender employees, which is a milestone victory for the gay rights movement that has been gaining favor in courts and electoral politics. The 64 to 32 vote to approve the Employment Non-Discrimination Act (ENDA) was the first time that federal policymakers had approved legislation to advance gay rights since repealing the military’s ban on gay men and lesbians in late 2010.

Approval of the bill came two days after Illinois became the 15th state to legalize gay marriage and four months after the U.S. Supreme Court sanctioned federal recognition of legally married couples. “This is a really tremendous milestone, a day I will never forget,” said Senator Tammy Baldwin (D-WI), who is the first openly lesbian senator. President Barack Obama praised supportive senators and called on House Republicans to quickly allow a vote. “One party in one house of Congress should not stand in the way of millions of Americans who want to go to work each day and simply be judged by the job they do. Now is the time to end this kind of discrimination in the workplace, not enable it,” said Obama in a statement.

READ MORE: Illinois Votes Yes On Gay Marriage

But ENDA faces an obstacle in the form of the GOP-controlled House still dominated by social conservatives. House Speaker John A. Boehner (R-OH) and his lieutenants think that the measure is too broad and unnecessary and that the people ENDA are trying to protect are already covered under existing federal, state and private workplace protection laws. Twenty one states and the District of Columbia already have laws prohibiting workplace discrimination based on sexual orientation, while 17 states and D.C. also ban discrimination based on gender identity. Hundreds of the country’s largest companies also have similar bans. The lengthy campaign to pass federal workplace protections began 17 years ago, but senators have been shifting their opinions as Republican senators Orrin G Hatch (R-UT) and John McCain (R-AZ) voted no on a bill similar to ENDA back in 1996, and now, they voted yes.

Opponents of ENDA, such as the conservative Family Research Council warned that ENDA “would transform the workplace into an environment in which certain self-identifications and conduct must be given special privileges by employers” that might require people to conceal religious or moral views. Those concerns are shared by Boehner, who maintained his staunch opposition to the proposal in a statement. Congressional Democrats have suggested that socially conservative Republicans are increasingly out of step with most Americans. “Our history books are littered with those public figures who said, we just can’t end that discrimination based on race; we can’t end that discrimination based on age, based on disability, based on gender. Think about their place in history today,” said Senator Richard J. Durbin (D-IL).

Read more about ENDA at the Huffington Post.

Reach Executive Producer Arash Zandi here. Follow him on Twitter here.