Republican lawmakers and attorneys general on Monday submitted amicus briefs to the U.S. Supreme Court arguing that LGBTQ workers are not protected by federal civil rights law.

In two separate briefs, 48 members of Congress and 15 attorneys general argue that Title VII of the Civil Rights Act of 1964 — which bans employment discrimination on the basis of “race, color, religion, sex, or national origin” — does not protect against workplace discrimination due to a person's sexual orientation or gender identity.

“[A]t the time Congress enacted Title VII, ‘sex,’ ‘sexual orientation,’ and ‘gender identity’ had different meanings,” the brief by the attorneys general states. “As a result, the word ‘sex’ in Title VII cannot be fairly construed to mean or include ‘sexual orientation’ or ‘gender identity.’ The Second Circuit and the Sixth Circuit erroneously conflated these terms to redefine and broaden Title VII beyond its congressionally intended scope.”

Both briefs also argue that the power to ban discrimination against LGBTQ people rests solely with Congress.

The issue of whether “sex” discrimination in Title VII is inclusive of anti-LGBTQ discrimination has caused a split in lower courts over the past several years, with some backing gay and trans workers and others the employers who have fired them.

The briefs submitted by the lawmakers and the attorneys general Monday concern three cases that the Supreme Court will hear in October. Two of the cases involve discrimination based on sexual orientation: a suit from Gerald Bostock, a gay man fired from his job as a child welfare services worker by Clayton County, Georgia, and a suit on behalf of the late Donald Zarda, a gay man fired from his job as a skydiving instructor by New York company Altitude Express. The third case involves Aimee Stephens, a transgender woman who was fired from a Detroit funeral home after she informed her employer that she was beginning her gender transition.

The Department of Justice submitted two briefs in the cases earlier this month: One argued that Title VII does not prohibit employment discrimination based on sexual orientation, while the other argued that it doesn’t prohibit employment discrimination based on gender identity.

In a brief submitted earlier this year by 153 congressional Democrats, the lawmakers argued if “a man is discriminated against in the workplace because he dates men, but his female co-workers who also date men are not discriminated against for the same conduct, sex is clearly both a ‘but for’ cause and a motivating factor in that discrimination.”

The argument by the attorneys general against such an interpretation relies on Judge Diane Sykes’ dissent in a ruling issued by the 7th U.S. Circuit Court of Appeals that expanded Title VII to cover discrimination on the basis of sexual orientation: “An employer ‘who hires only heterosexual employees’ is simply ‘insisting that his employees match the dominant sexual orientation regardless of their sex,’” the brief states.

That same brief argues that a court ruling against the 1960s interpretation of “sex” discrimination would deprive “the States of the opportunity to weigh in on that question through the political process,” and noted that Congress has repeatedly failed to pass a bill adding these categories to the bill.

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