Mitt Romney is retiring from politics once his term in the Senate ends in January of 2025, the Utah senator announced Wednesday.

"It really is a profound honor to serve Utah and the country, and I thank you for giving me the opportunity to do so," he said.

The former presidential candidate took a parting blast at his archrival, President Trump, calling him and President Biden equally unfit to meet the issues of the day.

Mitt Romney retiring

Romney, 76, said it was "time for a new generation of leaders," dinging Trump and Biden as unable to confront the national debt, "climate change," and the rise of China.

"Donald Trump calls global warming a hoax, and President Biden offers feel-good solutions that make no difference to the global climate," he said.

My message to Utahns on my Senate reelection plan: pic.twitter.com/kgbsfIxMeR

— Senator Mitt Romney (@SenatorRomney) September 13, 2023

Romney, a former Massachusetts governor, lost the 2012 presidential election to Barack Obama. Four years later, the GOP would be transformed by the rise of Trump and his confrontational, no-holds barred style.

Conscience? Or relic?

Like many Republican politicians at the time, Romney vocally opposed Trump in 2016. But after Trump's historic upset victory against Hillary Clinton, Romney met with Trump to discuss becoming Secretary of State - a job that ultimately went to Rex Tillerson.

Romney won election to the Senate in 2018, going on to position himself as the self-appointed conscience of a party gone adrift.

His old-fashioned civility earned him praise from liberals and the anti-Trump mainstream media, but among many Trump supporters, he was seen as a "RINO" or collaborator with left-wing radicals.

In 2020, Romney marched with Black Lives Matter protesters as riots swept the nation in the aftermath of George Floyd's death.

Black Lives Matter. pic.twitter.com/JpXUFlxH2J

— Mitt Romney (@MittRomney) June 7, 2020

Romney was the only Republican to vote to convict Trump in both of his impeachments, relating to Trump's dealings with Ukraine and January 6th. In both cases, Trump was acquitted.

Trump reacts

Trump did not hesitate to wish Romney, who was facing a tough primary in Utah, farewell - making a mocking reference to his notorious Twitter pseudonym, Pierre Delecto.

“Mitt Romney, sometimes referred to as Pierre Delecto, will not be seeking a second term in the U.S. Senate, where he did not serve with distinction,” Trump wrote, referencing Romney's Twitter pseudonym.

“A big primary fight against him was in the offing, but now that will not be necessary. Congrats to all. Make America great again!”

But Romney received praise from Mitch McConnell (R-Ky.), another Trump rival and stalwart of the old Republican party that Trump cast aside. McConnell, 81, has refused calls to step down after a series of health scares.

"The U.S. Senate is known to attract bright and proven public servants. However, we rarely get to welcome new Senators already as accomplished and well-regarded as Mitt Romney,” McConnell said.