REPUBLICAN CIVIL WAR, SENATOR FLAKES ATTACKS "RECKLESS, OUTRAGEOUS AND ,UNDIGNIFIED TRUMP"

Arizona senator Jeff Flake on Tuesday launched an extraordinary attack against Donald Trump and the "complicity" of the Republican party while announcing his decision to leave the Senate.

Flake, a key Republican critic of Trump, said he was retiring at the end of his term in 2018 because there was no room for him in the party under the current president's stewardship. He then delivered an emotional appeal from the Senate floor against the state of affairs under Trump, bemoaning that his Republican colleagues had "given in or given up on core principles in favor of a more viscerally satisfying anger and resentment".

"We must never allow ourselves to lapse into thinking that that is just the way things are now," he added. "We must stop pretending that the degradation of our politics and the conduct of some in our executive branch are normal.""It is time for our complicity and our accommodation for the unacceptable to end," Flake said. "There are times when we must risk our careers in favor of our principles. Now is such a time.

"Reckless, outrageous, and undignified behavior has become excused and countenanced as 'telling it like it is' when it is actually just reckless, outrageous, and undignified."

He said such behavior was "dangerous to our democracy" and projected not strength but a "corruption of the spirit". He then asked his colleagues: "When the next generation asks us: 'Why didn't you do something? Why didn't you speak up? What are we going to say?'"

Flake joins a list of high-profile Republicans who have jumped ship in recent months amid the turmoil of Trump's presidency. Bob Corker, the chairman of the Senate foreign relations committee, declared his retirement last month and has since been locked in a bitter feud with Trump that reached new heights on Tuesday.

Hours before Flake's announcement, Trump's war of words with Corker escalated in unprecedented fashion ahead of a meeting between the president and SenateRepublicans on Capitol Hill. Prior to the closed-door luncheon, Corker branded Trump as an "utterly untruthful president" on NBC's Today Show.

In a separate interview with CNN, Corker went even further, stating of the president: "I don't know why he lowers himself to such a low, low standard and debases our country in that way but he does."

Coupled with Flake's scathing remarks on the Senate floor, the growing list of Republicans sounding the alarm over Trump's presidency marked a potential watershed moment within the party. 

Several prominent Republicans have spoken out, albeit in veiled terms, against so-called "Trumpism" in recent weeks. McCain, who represents Arizona alongside Flake in the Senate, denounced "half-baked, spurious nationalism" in a speech last week that also decried the abdication of US leadership on the global stage. Days later, George W Bush condemned bigotry while declaring American politics "more vulnerable to conspiracy theories and outright fabrication".

Sarah Huckabee Sanders, the White House press secretary, played into the intra-party rift by dubbing Flake's decision as "a good move" while telling reporters his remarks were not "befitting of the Senate floor".

Speaking at the daily White House briefing, Sanders dismissed the criticisms made by Flake and Corker. "Look, I think the voters of these individual senators' states are speaking in pretty loud volumes," she said. "I think they were not likely to be re-elected and I think that shows the support is more behind this president than it is those two individuals."

In his Senate floor speech, Flake implored Republicans to do away with the political considerations that have enabled Trump to challenge to norms of governance and basic decorum.

"The alliances and agreements that ensure the stability of the entire world are routinely threatened by the level of thought that goes into 140 characters," Flake said. "Would we Republicans meekly accept such behavior on display from dominant Democrats? Of course we wouldn't. And we would be wrong if we did."

"When we remain silent and fail to act ... because of political considerations, because we might make enemies, because we might alienate the base," he added, "we dishonor our principles and forsake our obligations."

Flake was one of the few Republican senators who declined to endorse Trump during the 2016 presidential election. Earlier this year, he published a book framing the rise of Trump as a moment of reckoning for the Republican party.

Flake's candor highlighted the discord within the Republican party in the aftermath of Trump's successful insurgent campaign. 

Steve Bannon, Trump's former chief strategist, declared war on the Republican establishment after leaving the White House in August to take down incumbents perceived by the base as insufficient in their support of the president's agenda. A Bannon ally celebrated the news of Flake's retirement, texting the Guardian: "Another scalp!"

Although Flake had raised millions for his re-election campaign, his criticism of Trump loomed over what was poised to be a tough primary against rightwing challengers that included Kelli Ward, the former Arizona state senator who failed to unseat John McCain in November. Ward had dubbed Flake's refusal to endorse Trump in the 2016 campaign "treacherous".

Amplifying pressure from the right, Trump met with some of Flake's potential challengers ahead of a rally in Phoenix in August and subsequently attacked the senator on Twitter, writing: "Not a fan of Jeff Flake, weak on crime & border!"

Flake was a co-author of a comprehensive immigration reform bill in 2013 that would have provided a pathway to citizenship for roughly 11 million undocumented immigrants living in the US. He also differed from Trump on trade, but ultimately told the Arizona Republic newspaper his decision to leave the Senate was a moral choice.

Corker and Flake's decisions to step aside leave room for Republicans to run new candidates who might be less tarnished by the toxicity of Trump's tenure. 

Senate Leadership Fund, the Super Pac dedicated to preserving the Republican majority in the upper chamber, said Flake's decision would ultimately help to thwart Bannon's crusade against incumbent Republicans.

"The one political upshot of Sen Flake's decision today is that Steve Bannon's hand-picked candidate, conspiracy-theorist Kelli Ward, will not be the Republican nominee for this Senate seat in 2018," the group's president and CEO, Steven Law, said in a statement.

The move nonetheless removed yet another strong, household name from a seat being eyed as a potential pickup by Democrats, who are seeking to regain control of a Republican-led Congress. Democrats are rallying behind the Arizona congresswoman Kyrsten Sinema, known as a rare centrist voice in the increasingly polarized country's capital.

Several Republicans serving in the House of Representatives have announced plans to retire, including David Trott of Michigan, David Reichert of Washington, Charlie Dent of Pennsylvania and Ileana Ros-Lehtinen of Florida, leaving an opening for Democrats in competitive districts.Political operatives in Washington were surprised by Flake's announcement, which followed a slew of similar decisions from Republicans in swing states.

By contrast, at least one moderate Republican voice, Senator Susan Collins, has said she will seek re-election in Maine.

Alex Conant, a partner at Firehouse Strategies who worked on Marco Rubio's presidential campaign, said it was a "troubling trend" for reliable conservatives like Flake to feel as though they no longer had a place in the Republican party.

"It's no secret that there's a lot of divisions within the Republican party right now. A lot of Republican leaders are uncomfortable with the direction that Trump is leading us," Conant said.