WASHINGTON (AA) – Outgoing Republican congresswoman Liz Cheney threw her weight Thursday behind a Democratic lawmaker who is facing a tight re-election race in Michigan.

Cheney failed to win her party’s primary in August and while she has been a critic of Republicans aligning themselves behind former President Donald Trump, her endorsement of congresswoman Elissa Slotkin marks a first in her political career.

“I’m proud to endorse Elissa Slotkin,” Cheney said in a statement, according to the Hill news website. “Serving together on the Armed Services Committee, I have come to know Elissa as a good and honorable public servant who works hard for the people she represents, wants what’s best for the country, and is in this for the right reasons.”

Cheney has progressively found herself on the outs with the Republican Party as it has become increasingly beholden to former Trump’s MAGA (Make America Great Again) ideology. Cheney has been a stark critic of Trump and his claims of 2020 election fraud and has been a pivotal member on the House of Representative panel probing the Jan. 6, 2021, riots where Trump’s supporters stormed the Capitol.

Cheney has now become part of a growing camp of traditional Republicans who have endorsed Democrats rather than Trump or his political allies.

In 2019, Senator Jeff Flake, Former Governor John Kasich, ex-Defense Secretary Chuck Hagel and one-time Secretary of State Colin Powell were among dozens of Republicans who backed the then-Democratic nominee.

Flake would go on to become Biden’s envoy to Türkiye.

Slotkin is currently locked in a heated race against Republican candidate state senator Tom Barret in Michigan’s 7th congressional district. The race is considered a toss-up by the Cook Political Report, which is a non-partisan group that analyzes US elections.

The FiveThiryEight polling website said Slotkin is favored to win her re-election race.