Republican senator Jeff Flake hopes for 'tipping point' against Trump
Republican senator Jeff Flake has hit back at Donald Trump, saying "you can't continue to just remain silent" about the president's politics and behaviour.
"There is a tipping point. ... I hope we're reaching that tipping point," Mr Flake told NBC's Today programme.
The Arizona senator made the rounds of morning television news shows to talk about his decision not to run for re-election in 2018 and his impassioned speech on the Senate floor on Tuesday, in which he said he could no longer be "complicit" with the Republican president.
"We are excusing undignified and outrageous and reckless speech and behaviour as 'telling it like it is'. That's not right," Mr Flake said on MSNBC.
Mr Trump immediately fired back on Twitter, saying Mr Flake and another retiring Senate Republican, Bob Corker of Tennessee - who criticised the president on Tuesday as "untruthful" and debasing the nation - are not running for re-election because "they had zero chance of being elected".
He also claimed the two senators stand alone, boasting in several tweets that he received standing ovations at a Senate Republicans' luncheon on Tuesday at the Capitol.
Mr Flake cited the era of Joseph McCarthy, the Republican Wisconsin senator whose smear tactics alleging communist infiltration ultimately led to his censure.
In a column in the Washington Post, Mr Flake quoted Joseph Welch, an army lawyer who stood up to McCarthy in a June 1954 hearing and demanded: "Have you no sense of decency, sir?"
"The moral power of Welch's words ended McCarthy's rampage on American values, and effectively his career as well," Mr Flake wrote. "We face just such a time now. We have again forgotten who we are supposed to be."
He also said he thinks more of his Republican colleagues will speak out.
"It's up to us to stand us and say, 'This is not acceptable'," he told ABC's Good Morning America.
Asked why others in his party have not yet done so, Mr Flake said: "There is some fatigue about it."
But he stopped short of saying Mr Trump should be declared unfit for office or impeached, adding: "The voters made their choice. He was elected fair and square."