Caitlyn Jenner, the former Olympic athlete-turned-transgender activist, has just executed an athletic 180-degree political about-face, turning against President Donald Trump with a mea culpa column declaring, "I was wrong" about Trump's commitment to LGBTQ rights.

"Trump was the first Republican presidential candidate to claim to support this valuable, vulnerable community, and I was encouraged by the applause he received when he said at the Republican National Convention in July 2016 that he would stand up for the LGBTQ community," Jenner said in a column published in the Washington Post Thursday.

"Sadly, I was wrong. The reality is that the trans community is being relentlessly attacked by this president...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...

"This is politics at its worst. It is unacceptable, it is upsetting, and it has deeply, personally hurt me," Jenner said.

Jenner, 68, is a lifelong Republican who supported Trump (and attended one of his his inauguration parties).

Her support of the president irked some people in the LGBTQ community who'd embraced her when she transitioned in 2015 from Bruce Jenner, reality star and father and stepfather to 10 children, to Caitlyn Jenner, newly minted heroine and media star for a community that needed one.

But after watching Trump and his increasingly hostile administration over the past two years, she said, "my outlook has changed significantly from what it was during my highly publicized and glamorized early Caitlyn days, when my life as an out trans woman was just beginning."

Jenner's turnaround on Trump comes only two weeks after her stepdaughter Kim Kardashian's husband, rapper Kanye West, declared his Trump love in a bizarre rant during a meeting with him in the Oval Office.

(Kardashian herself also met with Trump in the Oval Office in May when she successfully lobbied the president to release a woman who was serving a life sentence for a first-time, nonviolent drug offense.)

Jenner wrote that polls showed Americans’ views on LGBTQ issues were changing, including in the voter base of the GOP. She was optimistic that she could "leverage my privilege for change."

But it hasn't happened, she lamented. "Believing that I could work with Trump and his administration to support our community was a mistake," she wrote.

She cited a recently leaked Department of Health and Human Services memo that proposed — "preposterously and unscientifically" — that the government mandate one's gender permanently to one’s genitalia at birth, thus defining transgender out of existence. She decried Trump's ban on trans people serving in the military and the rollback of President Obama-era protections for trans schoolchildren and bathroom preferences.

"It’s clear these policies have come directly from Trump" and were sanctioned by his base," she asserted. "My hope in him – and 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 pledged to "listen more" to the LGBTQ community.

"The world needs to hear us. The world needs to know us. We will not be erased."