Republican Sen. Jeff Flake went to the floor of the Senate Tuesday afternoon to warn the country about President Donald Trump and explain why he will not run for re-election in 2018.

“We must stop pretending that the degradation of politics in our executive branch are normal. They’re not normal,” Flake said.

“Silence is complicity. I have children and grandchildren to answer to, and so, Mr. President, I will not be complicit and silent,” he said, technically addressing the president of the Senate but also addressing the president of the United States.

And Flake, his voice sometimes quivering, decidedly broke the silence.

“Reckless,” “outrageous,” “undignified,” “mercurial,” and “appalling” were just a few of the ways Flake described Trump and his behavior.

“Mr. President, I rise today to say ‘Enough,’” Flake said.

In announcing he will not seek reelection to the Senate, Flake joins Republican Sen. Bob Corker of Tennessee, who announced last month that he also would not seek reelection and has subsequently been very critical of Trump.

The decision, he said, will free him from political considerations as he serves out the last 18 months of his six-year term.

“I don’t know why he lowers himself to such a low, low standard and debases our country in the way that he does, but he does,” Corker told CNN Tuesday morning, adding that he wouldn’t have supported Trump in last year’s election knowing what he knows now.

Flake was facing a primary challenge from an unapologetic Trump supporter, Kelli Ward, who had the backing of billionaire Robert Mercer and former White House Chief Strategist Steve Bannon.

He also would have faced well-funded Democratic congresswoman Kyrsten Sinema in the general election. At least one poll had shown that Flake was down in both the primary and general election. Flake suggested that winning reelection would have required him to compromise his principles too much.

Flake suggested he’d made enough compromises already.