On the same day former Massachusetts Gov. Mitt Romney filed to run for Senate in Utah, retiring Sen. Jeff Flake said the chamber needs someone like Romney to be an “independent voice.”

“We need Mitt Romney in the Senate,” the Arizona Republican said Thursday at an event at the National Press Club. “We need an independent voice, somebody who will enter the Senate chamber with immediate gravitas and someone who can work across the aisle, and actually, I think, create a whole new power center in the Senate. I think that’s desperately needed.”

Flake delivered a sharp rebuke of President Donald Trump in his speech Wednesday afternoon. Romney, the 2012 GOP presidential nominee, has also pushed back on Trump in the past.

Flake’s decision not to run for re-election in Arizona comes at a time when he says the Republican Party is defined by loyalty to Trump rather than conservative principles.

As a “free trade, limited government, economic freedom” Republican, he could not be elected right now, Flake said Sunday on Meet the Press.

Romney is expected to secure the GOP primary in Utah, where he owns a home, in a race to replace retiring GOP Sen. Orrin G. Hatch. Inside Elections rates the race Solid Republican. 

Though Flake is leaving the Senate, he again did not rule out a 2020 run for president. “Next question,” he said.

“Running for president is not in my plans but I have not ruled anything out,” Flake said. “I do think that there should be a conservative challenge. I think if, for no other reason, Republicans want to be reminded, I think, of what conservatism really means: limited government, economic freedom, free trade, reverence for the free press, immigration.”

Flake is traveling through New Hampshire Friday to speak at the Politics and Eggs series, a virtual right of passage for any presidential hopeful. The visit has added more fuel to the Flake 2020 speculation.

In the meantime, Flake said he was concerned about the prospect of Republicans holding onto his Senate seat.

Inside Elections rates that race Toss-Up.  Three Republicans — former Maricopa County Sheriff Joe Arpaio, former state Sen. Kelli Ward, and Rep. Martha McSally — square off in a primary that has become in part a Trump loyalty contest. 

The recent loss in a special election in Pennsylvania’s 18th District, which Trump won by 20 points, should be a “big wake-up call” for Republicans heading into the midterm elections, Flake said.

“We’re testing the limits of Trumpism,” he said during a question-and-answer session. “We’re realizing that you can only drill down on the base so far and you have to appeal to the broader electorate.”

But Flake suggested in his speech that Republicans kowtowing to Trump may not deserve to be in power anyway. 

“We have become strangers to ourselves, even as we pretend everything is fine and it is working as if it has always worked,” Flake said of Republicans. “To that, I say ’nonsense.’”

“If my party is going to try and pass off the degradation of the United States and her values from the White House as normal, if we’re going to cloister ourselves in the alternative truth of an erratic leader, if we are going to refuse to live in the world that everyone else lives in and reckon with the daily reality that they face — including their very real and understandable anxiety that they feel — then my party might not deserve to lead,” Flake said.