Caitlyn Jenner said in an editorial published Thursday in the Washington Post that she was wrong about believing in Donald Trump would protect LGBTQ community when he became President, calling her hope in him “misplaced” after reports surfaced last week that his administration is discussing a plan to redefine the definition of gender at the federal level.

“The leader of our nation has shown no regard for an already marginalized and struggling community,” wrote Jenner, who voted for Trump in 2016. “He has ignored our humanity. He has insulted our dignity. 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, claiming his anti-transgender policies are meant to “protect the country.” This is politics at its worst. It is unacceptable, it is upsetting, and it has deeply, personally hurt me.”

The op-ed came after the New York Times last week published the contents of a leaked memo from the Department of Heath and Human Services that argued gender should be defined “on a biological basis that is clear, grounded in science, objective and administrable,” with a person labeled female or male based on the genitals they are born with and listed on a birth certificate.

Other biological factors are known to contribute to defining a person’s sex (chromosomes, hormones, etc), as well as one’s gender identity. One doctor, Dr. Joshua Safer of Mount Sinai Hospital’s Center for Transgender Medicine and Surgery, told NBC News the memo’s suggested definition is “not consistent with current western medicine or science in terms of how we actually operate or define sex of individuals.”

The new definition would be used to administer Title IX, the federal law that prevents discrimination by gender, all but eliminating protections and recognition for an estimated 1.4 million Americans who identify as trans.

Jenner, who was Bruce Jenner when he won the 1976 gold medal at the 1976 Olympics and later became a film and TV personality, came out as trans in 2015. She later starred on the E! docuseries I Am Cait, which focused on her transition.

“Believing that I could work with Trump and his administration to support our community was a mistake,” wrote Jenner, who noted she was hopeful after Trump’s Republican National Convention speech in which he said he would stand up for the LGBQT community. She added that she traveled to Washington many times “to lobby and educate members of Congress, other Washington policymakers and powerful influencers,” which drew criticism from segments of the LGBQT community but which she said “almost always led to encouraging conversations.”

She said in the WaPo op-ed that the news of last week has changed her views.

“The recently leaked Department of Health and Human Services memo that suggests — preposterously and unscientifically — that the government ought to link gender to one’s genitalia at birth is just one more example in a pattern of political attacks. One doesn’t need to look back far to witness the president assault our nation’s guardians with a ban on trans people serving in the military or assail our nation’s future with a rollback of Obama-era protections for trans schoolchildren.

“It’s clear these policies have come directly from Trump, and they have been sanctioned, passively or actively, by the Republicans by whose continued support he governs. My hope in him — in them — was misplaced, and I cannot support anyone who is working against our community. I do not support Trump. I must learn from my mistakes and move forward.”

She added: “I am more determined than ever to find the best way to bring trans issues to the fore of our social and political conversation, domestically and abroad. “I need to listen more to the members of the LGBTQ community and to learn more. I need to better use my voice, my privilege and my foundation to advocate for and support our community.”

Trump said earlier this week amid the backlash that the issue was in flux, and that “we have a lot of different concepts right now.”