Caitlyn Jenner, the transgender rights activist who has long drawn criticism from members of the L.G.B.T.Q. community for her Republican leanings, unambiguously denounced President Trump on Thursday for his stance on transgender issues.
In an column published in The Washington Post, Ms. Jenner, 68, wrote that she had hoped she could work within the Republican Party to improve its position on L.G.B.T.Q. issues, but that she had evolved to see that belief as a mistake.
Ms. Jenner, an Olympic gold medalist and reality television star, delivered this blunt rebuke days after The New York Times reported that the Trump administration was considering narrowly defining gender as a biological condition determined by a person’s genitalia at birth. The news prompted rallies and online fury, with many — including Ms. Jenner — declaring that they “won’t be erased” by the federal government’s policies.
“The reality is that the trans community is being relentlessly attacked by this president,” Ms. Jenner wrote. “He has made trans people into political pawns as he whips up animus against us in an attempt to energize the most right-wing segment of his party.”
Ms. Jenner, a longtime Republican, has previously criticized Mr. Trump for his administration’s actions on transgender issues. Last year, she denounced Mr. Trump’s decision to rescind protections that allowed transgender students to use the bathroom of their choice.
But until the column she had not yet gone so far as to reverse her support for Mr. Trump, whom she said she voted for in 2016. Ms. Jenner also attended Mr. Trump’s inauguration despite a wave of celebrities declining invitations.
“My hope in him — in them — was misplaced, and I cannot support anyone who is working against our community,” she wrote in the column. “I do not support Trump.”
A spokesman for Ms. Jenner declined to make her available for an interview.
Last year, Ms. Jenner maintained some support for Mr. Trump in an interview with ABC’s “The View.” She expressed disappointment at his administration’s position on transgender students and bathrooms, but said she supported his nomination of a conservative Supreme Court justice, Neil M. Gorsuch. “I like a strong America. I like a strong military,” she said.
In the interview, Ms. Jenner declined to answer whether she’d vote for Mr. Trump again, saying, “Let’s see where we’re at” in a few years.
It appears that Ms. Jenner has made her decision earlier than she expected.
In the column, Ms. Jenner wrote that she had originally seen “fertile ground for change” in the Republican Party on L.G.B.T.Q. issues after Trump’s election. She said she was heartened by the applause he received during his speech at the Republican National Convention in 2016, when he said he would “stand up for the L.G.B.T.Q. community.”
In Mr. Trump’s speech, he did speak about supporting the L.G.B.T.Q. community, but specifically in response to the 2016 mass shooting at a gay nightclub in Orlando, Fla., by a man who declared allegiance to the Islamic State.
“I will do everything in my power to protect our L.G.B.T.Q. citizens from the violence and oppression of a hateful foreign ideology,” Mr. Trump said at the time.
Mr. Trump’s press office did not immediately respond to a request for comment on Ms. Jenner’s column.
In response to her declared support for Mr. Trump, L.G.B.T.Q. activists called Ms. Jenner out online, and sometimes in person, chastising her for identifying with a party that did not support their rights. After Ms. Jenner tweeted out a rejection of the Trump administration’s latest publicized position on the definition of gender, a viral tweet pointed out her longstanding endorsement of Mr. Trump.
Ms. Jenner pledged in her column to educate politicians and business leaders about the issues that affect the L.G.B.T.Q. community, like job discrimination and mental health, and use her privilege as a celebrity to advocate better for them.
“I must learn from my mistakes and move forward,” she said.