Conservative Sen. Mike Lee is taking a lone stand against a Trump nominee, blocking her from joining the office that takes workplace complaints because of her support for LGBTQ rights.

Lee has argued that the nominee, Chai Feldblum, wants to “use the might of government to stamp out traditional marriage supporters” and called for a nominee “who respects the institution of marriage and religious freedom for all Americans.”

President Trump put Feldblum in front of the Senate to serve on the Equal Employment Opportunity Commission, the federal office where Americans can turn for help with complaints about workplace discrimination on the basis of gender, race, religion, and other factors — including sexual orientation.

Feldblum, who currently serves as one of the EEOC’s five commissioners, was appointed to the commission by President Barack Obama in 2010 and nominated for another term this year by Trump.

A deadline is approaching: Nominees to the EEOC are typically confirmed as a group. If the Senate doesn’t confirm the current group, which includes Feldblum and two others, by December 31, the EEOC will no longer have the quorum required to make major decisions. That means many cases of systemic discrimination brought to the EEOC — including, potentially, sexual harassment cases — won’t be decided, and much of the work of the EEOC will grind to a halt.

The controversy over Feldblum has flown somewhat under the radar amid news of a possible government shutdown, but what happens with her confirmation in the coming days could affect whether millions of Americans have the protections they need from harassment and discrimination in 2019.

Senate Democrats are concerned: “Starting next year, the EEOC will be unable to fully perform its duties to protect workers whose civil rights are being violated in the workplace,” Sen. Patty Murray (D-WA) said in a statement to Vox. “In this moment, when sexual assault and harassment in the workplace are at the forefront of our national conversation, this is the wrong message to send to women, to workers, and to businesses.”

Confirming EEOC nominees is usually a formality

The EEOC ordinarily has five commissioners — three selected by the party that holds the presidency, and two selected by the minority party. The president typically agrees to nominate the minority party’s choices and sends them on to the Senate for confirmation, which is how Trump ended up nominating Feldblum.

Rather than going through a full confirmation process, the Senate usually fast-tracks the nominations, as Michelle Cottle explained at the Atlantic earlier this year. Essentially, senators vote on a combined slate of Republican and Democratic nominees at once to confirm them by unanimous vote. Republicans support the Democratic nominees with the understanding that the Democrats will support theirs, and vice versa.

This year, the slate of nominees includes Feldblum and two Republican picks for the EEOC, Janet Dhillon and Daniel Gade. Earlier this year, however, Sen. Lee announced that he wouldn’t vote to confirm Feldblum due to her positions on marriage and LGBTQ rights.

Feldblum is the first openly lesbian commissioner of the EEOC and a longtime advocate for LGBTQ rights. She helped draft the Employment Non-Discrimination Act, a proposed (but, as yet, never passed) federal law that would bar employers from discriminating against workers or applicants based on their sexual orientation or gender identity.

In a February statement, Lee argued that Feldblum was too radical for the EEOC, casting her as an opponent of religious freedom. Feldblum “has described modern-day politics as a ‘zero-sum game,’ where rights for LGBT Americans are secured only by curtailing the rights of religious Americans,” he wrote, claiming that she opposes all religious exceptions to laws if they infringe on the liberty of LGBTQ people.

In a statement published on Medium in August, Feldblum wrote that “various groups have mischaracterized my views in an effort to paint me as a radical opponent of religious liberty.”

When a person’s religious beliefs conflict with a law, she wrote, she actually favors a nuanced approach: “If there is a way to accommodate the person and still achieve the compelling purpose of the law, the government should do that. If there is no way to accommodate the person, and still ensure that the compelling purpose of the law is achieved, then the accommodation should not be made.”

Lee also casts Feldblum as an opponent of marriage in general, noting that she signed a 2006 document calling for “governmental and private institutional recognition of diverse kinds of partnerships, households, kinship relationships and families.” (The document, titled “Beyond Same-Sex Marriage” was also signed by dozens of other LGBTQ rights activists and scholars.)

“Don’t think for a second that Feldblum’s derogatory views about marriage will stay private,” Lee wrote. “Feldblum wants to turn her opinions into federal policy through the EEOC.”

A number of socially conservative groups have also opposed Feldblum’s nomination, with the American Family Association calling her “the Dragon Queen of Religious Bigotry” and “a one-woman Spanish inquisition.”

In fact, Feldblum wrote in August, her father was an Orthodox Jewish rabbi, and “those who know me know that respect for religion is a paramount and lifelong value for me.”

This response did not satisfy her critics. A spokesperson for Lee confirmed to Vox that the senator still opposes her confirmation.

Feldblum’s supporters, meanwhile, are arguing that failing to confirm Feldblum could have an especially big impact on the EEOC’s ability to fight sexual harassment. She co-chaired a bipartisan task force on sexual harassment at the EEOC. “She’s an incredible resource for the country on these issues,” Jenny R. Yang, a former chair of the commission under President Obama, told Vox.

Feldblum has also been a “leader on issues of disability accommodation” on the commission, Yang said, and failing to confirm her would mean losing that leadership. Feldblum is open about her own disability, an anxiety disorder.

If Feldblum’s term expires, the EEOC will be hamstrung

Two seats on the EEOC are currently vacant, and Feldblum’s current term expires at 11:59 pm on December 31. If the Senate doesn’t vote to confirm the new slate of nominees by then, the EEOC will have just two commissioners left. That means the commission won’t have a quorum and will be unable to make certain big decisions.

If Lee maintains his opposition, Senate Majority Leader Mitch McConnell has the option to put the nominees up for a regular confirmation vote. If that happens, Democrats believe they have the votes to confirm Feldblum, since Republicans have supported her in the past. But McConnell has to decide to hold the vote in the first place.

Trump could also pull Feldblum’s nomination and Democrats could make another pick — but Democrats worry that doing that could set a new precedent in which one senator could block any EEOC nomination, effectively ending the tradition of conflict-free appointments to the commission.

LGBTQ rights advocates are calling for McConnell to hold a vote. “With many Americans seeking justice after surviving discrimination and sexual harassment in the workplace, it’s imperative that Majority Leader Mitch McConnell force a Senate-wide vote and confirm Chai Feldblum,” said Sarah Kate Ellis, president and CEO of the LGBTQ media advocacy organization GLAAD, in a statement to media on Monday. “One anti-LGBTQ activist should not silence many people seeking justice under the law.”

The Senate is scheduled to be in session through the end of this week, though McConnell has warned that they may need to come back between Christmas and New Year’s Eve. If senators can’t agree on the commissioners by then, many survivors of discrimination and harassment nationwide will lose a key path to justice.

Without a quorum, the EEOC can’t issue new guidance documents like the workplace sexual harassment guidelines it issued after #MeToo gained steam last year. It can’t file amicus briefs in court or hire expert witnesses. And while regional EEOC offices can rule on smaller discrimination cases, the commissioners themselves have to rule on many larger cases that involve claims of systemic discrimination.

One recent example is the case of the New York City-based company Mavis Discount Tire Inc., which was accused of refusing to hire women for jobs as managers, mechanics, and tire technicians. The EEOC filed suit in federal court on behalf of women who said they’d been discriminated against by Mavis, and in 2016, the company agreed to pay $2.1 million to settle the case.

Without a quorum, the EEOC won’t be able to file suits like this one, and many people who believe they are the victims of systemic discrimination will lose the ability to seek recourse through the EEOC.