By Juliet Jacques, Ms. Jacques is the author of “Trans: A Memoir.”

LONDON — It must look odd to an outsider.

The race to replace Jeremy Corbyn as leader of the Labour Party, after its traumatic defeat in December’s general election, has largely been conducted in the spirit of bury-the-hatchet pragmatism, to the point of tedium. The three candidates have promised, however sincerely, to maintain the general thrust of the party’s policy platform; divisions have mostly been a matter of tone, style and subtle implication. Rancor and controversy have been restrained among the candidates as well as the 500,000-strong membership. Except in one area: trans rights.

A contentious row began last month, when the Labour Campaign for Trans Rights announced itself with 12 pledges, which ranged from recognizing trans people’s oppression — at risk of hate crime and denied equal access to public services, health care, housing and employment — to supporting the expulsion of members who express transphobic views. Rebecca Long-Bailey, the candidate closest to Mr. Corbyn’s politics, and Lisa Nandy, the one farthest away, supported the campaign. The outcry was immediate: People started the hashtag #expelme on Twitter. Hecklers disrupted leadership hustings. And Tony Blair, a former leader and prime minister, warned of “the cul-de-sac of identity politics.”

To many, the sight of a center-left party failing to support trans rights without equivocation must be baffling — not least to American Democrats, whose party, divided in many ways, is firmly united in its support for trans and nonbinary people. But really, it’s no surprise. Transphobia, constantly amplified by the country’s mainstream media, is a respectable bigotry in Britain, shared by parts of the left as well as the right.

There are two main types of British transphobia. One, employed most frequently but not exclusively by right-wing men, rejects outright the idea that gender might not be determined only by biological traits identifiable at birth. This viewpoint can often be found in publications aligned with the Conservative Party, such as The Spectator, The Times and The Telegraph, all of which are looking for a new “culture war” to pursue now that the long, exhausting battle over Brexit has finally been resolved in favor of Leavers. Read more via New York Times