☕🐸 Arizona #SenatorJeffFlake said "reckless, outrageous and undignified behaviour" at the top of the US government was dangerous to democracy.
Mr #Trump has previously called Mr Flake "toxic". The US president is already embroiled in a rowwith another Republican Senator, Bob Corker.
Before confirming his decision in a speech to the Senate, Mr Flake told the #ArizonaRepublic "there may not be a place for a Republican like me in the current #Republican climate or the current #RepublicanParty". Taking to the floor, he said he did not enjoy criticising the president but felt it was "a matter of duty and conscience". "We must never regard as "normal" the regular and casual undermining of our democratic norms and ideals," he said.
He lamented the "flagrant disregard for truth or decency, the reckless provocations, most often for the pettiest and most personal reasons". "I have children and grandchildren to answer to, and so, Mr President, I will not be complicit," he added.
Another prominent party critic of Mr Trump, #JohnMcCain, was quick to pay tribute to Mr Flake.