Tuesday brought fresh evidence President Trump has taken over the Republican Party, but pockets of active resistance remain as the tension and creative destruction that began with his upstart campaign continues over ten months into his presidency.

Trump began the day clashing with Sen. Bob Corker R-Tenn., who described him as an "untruthful president." Hours later, Sen. Jeff Flake, R-Ariz., abruptly announced he would not seek re-election next year, decrying the "coarseness of our leadership" from the Senate floor.

But sandwiched between those two events was the Senate GOP policy luncheon, where Trump was greeted "without fireworks" as the party's leader. Flake cited the president's rebranding of the party along more nationalist and populist lines in his decision to forgo a second Senate term.

"It is clear at this moment that a traditional conservative, who believes in limited government and free markets, who is devoted to free trade, who is pro-immigration, has a narrower and narrower path to nomination in the Republican Party, the party that has so long defined itself by its belief in those things," he lamented on the Senate floor.

"Here's the bottom line: The path that I would have to travel to get the Republican nomination is a path I'm not willing to take, and that I can't in good conscience take," Flake told the Arizona Republic. "It would require me to believe in positions I don't hold on such issues as trade and immigration, and it would require me to condone behavior that I cannot condone."

Flake's decision follows thinly veiled criticism of Trump by former President George W. Bush, the last Republican in the White House, and fellow Arizona Sen. John McCain, the 2008 GOP presidential nominee. But even more explicit rebukes of Trump by party elders failed to slow his path to the nomination last year and appeared to take their toll on Flake ahead of 2018.

The freshman senator was beset on all sides, opposed by Arizona Democrats motivated by anti-Trump fervor and Republicans, many of whom didn't think he was supporting the president enough. Only 30 percent of the state's voters approved of Flake's performance in office with 53 percent disapproving, according to Morning Consult. Strikingly, 50 percent of Republicans disapproved in addition to 60 percent of Democrats.

"I haven't spoken with [the president] directly since the announcement by Sen. Flake, but I think that based on previous statements, and certainly based on the lack of support that he has from the people of Arizona, it's probably a good move," White House press secretary Sarah Sanders told reporters during Tuesday's briefing.

Other Trump allies rejoiced. "Sen. Flake's retirement paves the way for a candidate who truly supports an America First agenda to come to Washington, stand beside our president, and make America great again," said Erin Montgomery, communications director for America First Action.

Sam Nunberg boasted that former White House chief strategist Steve Bannon, the Breitbart News head who is actively recruiting primary challenges to incumbents who are loyal to Republican Senate leadership, now has "three scalps."

"It's no coincidence that Flake officially dropped out only a week after Laura Ingraham and Steve Bannon campaigned for [pro-Trump Arizona Senate candidate] Kelli Ward," Nunberg told the Washington Examiner. "This Bannon Movement is real."

Ward herself took a victory lap. "Arizona voters are the big winner in Jeff Flake's decision to not seek re-election. They deserve a strong conservative in the U.S. Senate who supports President Trump and the 'America First' agenda," she said in a statement. "Our campaign proudly offers an optimistic path forward for Arizona and America."

"I'm surprised," said Republican strategist Alex Conant in response to Flake's decision. "Also disappointed, since I thought he had a good chance of getting re-elected. Ward is a terrible candidate, and Flake is a good fit for the state."

"I'm not surprised at all," said a second Republican operative who requested anonymity to speak candidly. "I think that Corker probably showed him how good the freedom of not having to be publicly abused by your own party's president all the time, while at the same time, having to defend the guy."

"I think there will be more to come and that Trump will be a little surprised at having to deal with two houses of Congress who are controlled by Democrats," the operative continued. "I also think congressional Republicans will be a little surprised at how quickly he moves to embrace a lot of the positions of the Left."

Flake's departure does open the door for other Republicans to run for the seat, some of whom might potentially be stronger in a primary against Ward or in a general election against the Democrats. Republican sources told the Washington Examiner that Flake had concluded he had no path forward in either race, polling periodically this year to assess his political standing.

"If there is a silver lining regarding the retirement of a good public servant, it is that Kelli Ward's chances of being a senator just dropped to near zero," said Republican strategist Christian Ferry. "Bad news for chemtrail enthusiasts."

That doesn't change the fact that the two most outspoken Republican Trump critics in the Senate are leaving after the next election, with Flake concluding that the GOP is at least, for now, Trump's party.

While Corker warned of "World War III" and suggested White House chief of staff John Kelly was running an "adult daycare center," Flake offered a more refined critique of Trump.

"Without fear of the consequences and without consideration of the rules of what is politically safe or palatable, we must stop pretending that the degradation of our politics and the conduct of some in our executive branch are normal," he said on the Senate floor Tuesday. "They are not normal."

"He's a great and honorable man," McCain told the Washington Examiner about Flake. Asked if this means the party is changing, Arizona's senior senator replied only, "I dunno. I dunno."

"For now, like it or not, the GOP is the party of Donald John Trump and Sen. Jeff Flake just flat out refused to accept it," said Republican strategist Ford O'Connell. "Couple that with the fact that Flake wrote a book trashing Trump and continued to thumb his nose at the president and the will of the voters in his own state, and Flake really has no one to blame but himself for his current political predicament."

A large subset of Republicans has objected to Trump's personal character, confrontational style, and departures from traditional conservative orthodoxy since he announced his candidacy in June 2015. So far, they have wound up on the losing side.

"It depends what people go to war over," said Rep. Steve Stivers, R-Ohio, who chairs the National Republican Congressional Committee. "When Republican members of Congress go to war over things that the Republican base isn't with them on, they don't win on that. You've got to understand the turf you're fighting on and who you're fighting for and what you're fighting for."

"I think some of the members who've been picking petty battles with the president have done it on issues that aren't really things that are [what our] voters are with them on, so that matters," Stivers added. "I guess Flake was more stylistic, but the president just has a bigger bully pulpit. And that's the bottom line on that one, because on a lot of the things Sen. Flake was going after him on it was more stylistic, but it got to be bickering, I think, and that didn't work well for Sen. Flake."

Trump has benefited from the perception that he is a fighter while a lot of his GOP detractors in Washington are not.

"The fight in both parties is not about policy," Bruce Haynes, a Republican strategist, said. "It's how we talk about the ‘them.' The tougher you are on the ‘them,' the better you are doing. And that is a product of the electorate not the preference of politicians. The politicians who are meeting the market are being rewarded with votes. Until the market changes, we can expect to see more of the same behaviors and more of the same winners."

This bad blood has so far left Republicans without major legislative accomplishments, like Obamacare repeal or tax reform, but the polls generally show GOP voters siding with Trump over Congress.

"Flake's impassioned speech before the Senate about ‘principle' misses the mark given the current political environment we are in," said O'Connell. "Trump's supporters know that the president has flaws, but they still believe that he is truly the last best chance to get things done. And if it comes down to Flake or Trump, Flake must go."

Lawmakers seemed a little less happy to see Flake go, including even the likely Democratic nominee for his Senate seat. "It has been an honor and a privilege to serve with Jeff over the years," Rep. Kyrsten Sinema, D-Ariz., told reporters on Capitol Hill. "He's a man of great integrity and great character and an Arizonan through and through."

"He approaches every issue with great courage and intelligence and I will really miss serving with him," said Sen. Susan Collins, R-Maine, a leading centrist. "I'm sad."

"It's always a little tough when you're at odds with the president and, in this case, he is," said Rep. Tom Cole, R-Okla. "But I think there is certainly always a place for people with Jeff Flake's character and his commitment to principle and his ideas."

"I'm sorry the personal relationship between the two didn't work out the way you would hope it would," Cole added. "He's got a lot to be proud of in his career both in the House and the Senate. He's picking the time of his own departure, a lot of people around here aren't that fortunate."

Republicans insisted their party remained a big tent. "If I've got Republicans who are voting with me 70 percent of the time, I love ‘em," said Sen. Thom Tillis, R-N.C. Sen. Richard Shelby, R-Ala., concurred, adding, "But I also believe we ought to be respectful and civil to each other."

Some didn't think it seemed it was necessarily a bad thing to have a little turnover with Corker and Flake.

"In fact, I think the Senate would be a better body if members were more focused on policy and doing the right thing for the American people and not always worried about re-election," said Sen. Steve Daines, R-Mont. "Every senator should be focused on doing the right thing for the country, not just for today but for the long haul."

The White House is on the same page. "I think that the people both in Tennessee and Arizona supported this president, and I don't think that the numbers are in the favor of either of those two senators in their states," Sanders said at Tuesday's briefing. "And so I think that this was probably the right decision."

David M. Drucker, Susan Ferrechio, and Al Weaver contributed to this report.