WASHINGTON — The Trump administration abruptly waded into the culture wars over gay rights this week, signaling in three separate actions that it will use the powers of the federal government to roll back civil rights for gay and transgender people.
Without being asked, the Justice Department intervened in a private employment lawsuit on Wednesday, arguing that the ban on sex discrimination in the Civil Rights Act of 1964 does not protect workers on the basis of their sexual orientation. The friend-of-the-court brief, filed at the United States Court of Appeals for the Second Circuit in New York, was a striking shift in tone from the Obama administration, which had shied away from that question.
The move ended a day that began with a tweet from President Trump announcing a ban on transgender people serving in the military, surprising Pentagon leaders and reversing a year-old Obama administration policy.
Also on Wednesday, Mr. Trump announced that he would nominate Sam Brownback, the governor of Kansas and a vocal opponent of gay rights, to be the nation’s ambassador at large for international religious freedom.
The constellation of events raised alarm among gay rights advocacy groups, which portrayed the moves as a concerted effort to limit advancements in gay rights.
“Yesterday was this administration’s anti-L.G.B.T. day,” James D. Esseks, director of the American Civil Liberties Union’s Lesbian Gay Bisexual Transgender & HIV Project, said on Thursday. “Whether coordinated or not, to have it all happen on the same day certainly brings into focus the profoundly anti-L.G.B.T. agenda of this administration.”
Administration officials insisted that the timing of the three actions was coincidental. Wednesday just happened to be the deadline for the Justice Department to submit briefs in the employment discrimination case, they said, and Mr. Trump’s tweets about transgender troops unexpectedly skipped past lawmakers and the military brass who were considering the issue.
But whether by accident or intent, the result was a striking reversal from Mr. Trump’s predecessor, who repeatedly used administrative actions and legal arguments to press for protections for gays and lesbians.