Sen. Mitt Romney (R-UT), who announced last year that he would retire and not seek re-election to another term, has long clashed with former President Donald Trump, including through frequent criticism before, during, and after his presidency, and even by voting in favor of Trump's impeachment and removal following the Jan. 6 Capitol riot in 2021.

On Saturday, Trump took a parting shot at the outgoing "Total Loser" senator as he endorsed his preferred Republican candidate to replace him, Riverton Mayor Trent Staggs, the Daily Caller reported.

The endorsement from Trump was timed to coincide with the Utah GOP convention on Saturday, during which party delegates from across the state would pick their preferred candidate ahead of the primary election in June.

Trump makes his pick to replace "Total Loser" Romney

In a Saturday morning Truth Social post, former President Trump wrote, "Trent Staggs is 100% MAGA, and is running to fill The Mitt Romney, a Total Loser, Seat as the next Senator from the Great State of Utah!"

"A Highly Successful Entrepreneur, who has served brilliantly as Mayor of Riverton for the past six years, Trent knows how to Create Jobs, Stop Inflation, Grow the Economy, and Secure the Border," he continued. "As your next Senator, Trent will help us Unleash American Energy, Support our Military/Vets, and Protect our always under siege Second Amendment."

"Trent Staggs has my Complete and Total Endorsement -- He will be a GREAT Senator, and never let you down!" Trump added.

Utah GOP convention picks Staggs just hours after Trump endorsement

It would appear that former President Trump's endorsement of Mayor Staggs carried some weight, at least with Utah GOP delegates, as the Associated Press reported that Staggs won the convention just a few hours later with the support of around two-thirds of the roughly 4,000 delegates.

Staggs, who announced his plan to run for Sen. Romney's seat even before the senator revealed his plan to retire, urged the convention-goers ahead of the vote, "Let’s replace Joe Biden’s favorite Republican with Donald Trump’s favorite Republican in Utah."

Of course, winning the convention is no guarantee that Staggs will also win the primary election, and a substantial battle is brewing between the two wings of Utah's GOP -- the more moderate side that would prefer another Romney-like centrist in the Senate versus the more populist-conservative Trump-aligned side of the party.

Staggs was not polling well ahead of the convention

The convention win for Mayor Staggs may be surprising to some, given how poorly he has performed in the handful of polls that have been conducted of Utah's Republican voters.

The most recent survey came in mid-April from Noble Predictive Insights and shows Staggs in fourth place with just 5% support -- well behind moderate Rep. John Curtis (R-UT) at 27%, attorney Brent Hatch (the son of late former GOP Sen. Orrin Hatch) with 11%, and former Utah House Speaker Brad Wilson at 10% support, though the pollsters also found that 41% of voters remained undecided.

Staggs' support in that poll was only marginally better than the 3% he garnered in a January survey by Deseret News, which had Curtis at 18%, Hatch at 14%, and Wilson at 8%, with 52% undecided. Staggs told the outlet at that time, "While our border sits open, Washington’s concern is securing Ukraine’s border. While Americans struggle with inflation, Congress lines their pockets through insider trading. Utah is hungry for representatives willing to stand up and say 'no more.' That’s what I’ve done as mayor. That’s what I’ll do in the Senate."

No endorsement from Romney

While former President Trump clearly has no qualms about wading into the middle of a primary race to pick his preferred candidate, the same cannot be said for Sen. Romney, who likely will not issue an endorsement in the contest to replace him.

In January, Romney's chief of staff, Liz Johnson, told local CBS affiliate KUTV, "Utah is fortunate to have several candidates who are interested in serving in the Senate, and Senator Romney appreciates their willingness to serve," but added, "He is staying out of the race."