"The answer is clear."

[packbat]

The U.S. Supreme Court issued a ruling today on three cases related to LGBT+ rights - Gerald Lynn Bostock v. Clayton County, Georgia; Altitude Express, Inc., et al. v. Zarda et al., as Co-Independent Executors of the Estate of Zarda; and R. G. & G. R. Harris Funeral Homes, Inc. v. Equal Employment Opportunity Commission et al. - answering the question of whether Title VII the Civil Rights Act of 1964 prohibits employment discrimination against gay and trans people when it prohibits discrimination by sex. In, unexpectedly, Justice Neil Gorsuch's words, the answer is "yes, it is illegal to discriminate against them" (us):

An employer who fires an individual for being homosexual or transgender fires that person for traits or actions it would not have questioned in members of a different sex. Sex plays a necessary and undisguisable role in the decision, exactly what Title VII forbids.

cosmolinguist has a nice roundup post bringing up a lot of good points about how much this means (tl;dr: a lot).