LGBT advocates will be watching a Senate committee Wednesday when it votes on long-sought legislation to protect LGBT workers from discrimination.

The Senate Health, Labor, Education & Pensions Committee will hold its markup Wednesday at 10 a.m. on the Employment Non-Discrimination Act. A successful vote would mark the first time a version of ENDA with transgender protections advanced in Congress.

Here are three things to watch for during the markup before the final vote:

1. What will Republicans do?

Given that all 12 Democrats on the committee — in addition to one Republican, Sen. Mark Kirk (R-Ill.) — are co-sponsors of ENDA, the legislation will almost assuredly be reported to the Senate floor regardless of Republican action if the final vote is on the bill as it was introduced.

Progressive advocates like lesbian Sen. Tammy Baldwin (D-Wis.) and Sen. Elizabeth Warren (D-Mass.) will almost certainly take the opportunity to weigh in on their first opportunity to vote on a bill entirely dedicated to LGBT issues since the start of the 113th Congress.

But support for ENDA from one Republican member of the committee during the markup — Sen. Lisa Murkowski (R-Alaska) — is seen as crucial for ENDA’s prospects for finding 60 votes to end an expected filibuster on the Senate floor. It’ll be difficult for her to change her vote in the full Senate once her position becomes known based on her vote in committee.

Murkowski’s office didn’t respond to a request for comment on ENDA, but she’s known for being supportive of LGBT rights. Just before the Supreme Court rulings on the Defense of Marriage Act and California’s Proposition 8, Murkowski became the third sitting U.S. Senate Republican to come out in favor of marriage equality. She’s also voted for hate crimes protection legislation and “Don’t Ask, Don’t Tell” repeal.

One LGBT advocate, who spoke on condition of anonymity, said Murkowski staffers have said she voted in favor of the Anchorage LGBT non-discrimination ordinance that came before voters in the city last year and was voted down.

Michael Cole-Schwartz, an HRC spokesperson, said his organization is lobbying senators on both sides of the aisle as the Senate markup approaches.

“The first Senate mark-up of an inclusive ENDA is a tremendous step toward floor passage and HRC has been lobbying senators on the bill, Republicans and Democrats alike,” Cole-Schwartz said. “Our efforts include both meetings with staff and senators in Washington as well as generating grassroots support in targeted states around the country.”

Tico Almeida, president of Freedom to Work, said his organization has been lobbying Republicans on ENDA.

“I’ve also asked Freedom to Work’s Republican Legislative Director, Christian Berle, to lobby any and every Republican member of Congress who will take our meeting to hear why ENDA is good for business and consistent with American values about hard work and success,” Almeida said.

Almeida declined to comment on which Republicans his organization has met with, but said there are more GOP members of Congress who’ll vote for a trans-inclusive ENDA than are commonly known.

But Almeida also gave credit to the American Unity Fund, a newly formed Republican LGBT group funded by Republican philanthropist Paul Singer, saying he’s “really impressed by their work on ENDA, and I’m told there’s much more to come.” That group didn’t respond to a request for comment.

The actions of GOP members during the markup are important because Republicans who oppose the legislation may take the opportunity to offer “poison pill” amendments that, if adopted, would make ENDA less palatable for final passage or limit its scope.

Sen. Lamar Alexander (R-Tenn.), the top Republican on the committee, may be the one to carry water for the Republican opposition to ENDA during the committee markup and during the vote on the Senate floor. In the previous Congress, Alexander earned a score of 15 out of 100 on HRC’s congressional scorecard.

Prior to the July 4 recess, Alexander was tight-lipped while speaking with the Washington Blade on Capitol Hill.

“I’m reviewing that now; I’m reviewing that now,” Alexander said.

Asked whether he’s leaning one way or the other on the legislation, Alexander said, “No. I’m still reviewing it. I’m working on immigration and that doesn’t come up until — that’s about a month away.”

2. Will ENDA be updated following Supreme Court decisions on job bias?

As amendments are offered up to ENDA during the markup, technical changes will likely be made to the legislation in the aftermath of recent Supreme Court rulings related to employment discrimination.

One such ruling was in 2009 in the case of Gross v. FBL Financial Services, which raised the standard of proof for making a claim of age discrimination in the workplace based on the Age Discrimination in Employment Act.

The ruling was issued in such a way that, if the current version of ENDA were to become law, would also make allegations of LGBT workplace discrimination more difficult to pursue. The LGBT group Freedom to Work has called for a change in the wording of ENDA to ensure meritorious cases of LGBT workplace discrimination would succeed.

In a statement, Senate HELP Committee Chair Tom Harkin (D-Iowa) said he supports the idea of updating ENDA in accordance with other legislation he previously introduced known as the Protecting Older Workers Against Discrimination Act to address issues the Gross ruling created.

“Last Congress, I introduced  a bill with Sen. Grassley to reverse the Supreme Court’s decision in Gross v. FBL Financial, and I intend to do so again soon,” Harkin said. “I believe the same standard of proof already applicable for plaintiffs alleging discrimination based on race, sex, national origin and religion should also apply to age and disability, as well as sexual orientation and gender identity.”

Another issue is whether ENDA will be updated in the wake of more recent Supreme Court rulings last month in the case of Vance v. Ball State University and the case of University of Texas Southwestern Medical Center v. Nassar.

In the Vance case, the court ruled that a person must be able to hire and fire someone to be considered a supervisor in discrimination lawsuits. In the Nassar case, the court limited how juries can decide retaliation lawsuits and said victims must prove employers only took action against them only for the intention to retaliate.

Writing the dissent in these rulings, Associate Justice Ruth Bader Ginsburg said the decisions dilute the strength of Title VII of the Civil Rights Act, adding the “ball is once again in Congress’ court to correct the error.”

Harkin’s office didn’t respond to a request for comment on whether the senator would support updating ENDA to ensure meritorious cases of LGBT workplace discrimination would succeed in the wake of those decisions.

Almeida predicted the committee would make technical changes to ENDA “to fix some loopholes and mistakes in ENDA’s current text” in a way that would update it in the wake of these Supreme Court decisions.

“In fact, I imagine some Republican senators will want to see technical corrections to certain drafting mistakes that accidentally make ENDA slightly more liberal than it should be,” Almeida said. “I think these technical corrections will be non-controversial and will help us create a better, smarter ENDA that can pass the Senate with 60 or more votes this year.”

Matt McNally, a spokesperson for ENDA’s chief sponsor Sen. Jeff Merkley (D-Ore.), said in a statement to the Blade the senator is prepared to make changes that Harkin deems fit.

“Sen. Merkley supports the current bill and will be working with his colleagues on the HELP committee, under the leadership of chairman Harkin, on any potential changes to the bill during markup,” McNally said.

3. Will lawmakers narrow ENDA’s religious exemption?

Another issue to watch — although the chances of any movement are unlikely — is whether efforts to limit ENDA’s religious exemption will gain  traction. LGBT groups are divided on whether the provision should stay as it is, or be restricted to enable greater protection against anti-LGBT workplace discrimination.

Currently, ENDA has a religious exemption that provides leeway for religious organizations, like churches or religious schools, to discriminate against LGBT employees. That same leeway isn’t found under Title VII, which prohibits religious organizations from discriminating on the basis of race, gender or national origin.

Ian Thompson, legislative representative for the American Civil Liberties Union, said lawmakers should at least consider rethinking the idea of narrowing the religious exemption during the upcoming markup.

“What we have seen over the past several months is an increasing array of voices weighing in on the need to appropriately narrow ENDA’s sweeping religious exemption — from prominent editorials in the Los Angeles Times and New York Times to the chairman emeritus of the NAACP, Julian Bond,” Thompson said. “As more pro-equality members of Congress understand the potential harms of the current exemption, I think there will be even more support for narrowing it. That foundation is being laid now.”

Immediately after the introduction of ENDA in April, the ACLU — along with Lambda Legal, the National Center for Lesbian Rights and the Transgender Law Center — made public a letter saying they have “grave concerns” about ENDA’s religious exemption.

Informed sources, speaking on condition of anonymity, have told the Washington Blade the ACLU proposed a change in language related to the religious exemption prior to the bill’s reintroduction at the beginning of the year, but Merkley rejected the proposal out of concern that Republicans would bolt from the bill.

In a statement to the Blade, Harkin indicated a lack of interest in restricting ENDA’s religious exemption by emphasizing he opposes discrimination against LGBT employees by secular employers.

“I believe that — as with all other anti-discrimination protections — a capable employee working for a secular, non-religious organization, should not be fired, or not hired, because of his or her sexual orientation or gender identity,” Harkin said.

Voting in favor of narrowing the religious exemption would also be difficult for lesbian Sen. Tammy Baldwin (D-Wis.), who’s a member of the HELP committee, because as a U.S. House member in 2007 she voted in favor of the current religious exemption when it was offered up as an amendment on the floor.

Despite these calls to limit the religious exemption in ENDA, many prominent LGBT groups working on ENDA say they support the religious exemption as it stands. Among them is Freedom to Work’s Almeida, who noted many religious groups support ENDA because of the exemption.

“Some churches and religious organizations will choose discrimination and some churches will choose inclusion of all of God’s children,” Almeida said. “ENDA does not force the choice of the federal government upon any church, and therefore ensures that ENDA will not be struck down someday by the U.S. Supreme Court for violating religious freedom.”

In a report dated June 11, 2012, the Center for American Progress also endorsed the religious exemption, saying it’s “politically” necessary for ENDA to advance and secure employment protections for LGBT Americans.

“At its core ENDA is about ensuring that all Americans can go to work in an environment free of discrimination,” the report states. “By including such a broad exemption for religious organizations, ENDA is also about protecting religious freedoms.”

One of the authors of the report is Jeff Krehely, who has since departed the Center for American Progress to join as vice president and chief foundation officer for the Human Rights Campaign.

Paul Guequierre, an HRC spokesperson, affirmed Krehely’s views on the religious exemption reflect the view of HRC and said the National Center for Transgender Equality and the National Gay & Lesbian Task Force share that position. NCTE affirmed it supported the exemption.

Mark Daley, a Task Force spokesperson, said his group supports the bill but wants to see the religious exemption narrowed as ENDA progresses.

“The Task Force strongly supports S. 815 and will be working hard for its passage this year,” Daley said. “We also favor narrowing the religious exemption as ENDA moves towards becoming law. We will be working to get the votes needed to pass S. 815 in the 113th Congress.”

If the Senate does take action to limit the religious exemption, it might happen on the Senate floor. During an event hosted by the moderate group Third Way last week, Sen. Kirsten Gillibrand, who isn’t a member of the HELP committee, expressed support for the idea of removing ENDA’s religious exemption.

During the Q&A session, audience member Ellen Sturtz — the lesbian activist affiliated with GetEQUAL who gained notoriety by confronting first lady Michelle Obama — asked Gillibrand whether she’s willing to amend ENDA to remove the religious exemption.

The New York senator responded simply, “Oh, yes. Yes, I am.” Asked by the Blade to elaborate, Bethany Lesser, a Gillibrand spokesperson, said, “Sen. Merkley is leading the ENDA bill and Sen. Gillibrand will offer any help she can provide to help him pass it.”