Republican Sen. Jeff Flake again attacked President Donald Trump after announcing Tuesday he will not seek re-election.

Asked why he isn’t running for re-election the Arizona lawmaker said, “stay tuned,” and walked into the Senate Chambers. Flake is one of Trump’s most vocal critics.

“The flagrant disregard for truth and decency,” should never be regarded as normal, Flake said on the Senate floor minutes after his announcement. His voice shook. “Anger and resentment are not a governing philosophy.”

Flake said he plans to serve out the remainder of his term but will not contend in 2018.

Fellow Arizona Senator John McCain tweeted following Flake’s announcement: “Thank you to my dear friend @JeffFlake for your honorable service to the state of #Arizona the nation.”

Thank you to my dear friend @JeffFlake for your honorable service to the state of #Arizona & the nation.

— John McCain (@SenJohnMcCain) October 24, 2017

Flake called his continued criticism of the president a matter of obligation. He said a failure to do so was profoundly misguided and that his fellow Republicans would never allow Democrats to behave like Trump.

“He’s always open-hearted, is respectful, is willing to work across the aisle, is a terrific partner and has just been great company,” Delaware Sen. Christopher Coons said.

Coons and Flake serve together on the Foreign Relations Committee.

“If there isn’t room for senators of the United States who have strong opinions, and who keep to their principles, then this is a worse place for our country,” Coons said.

Senate Majority Leader Mitch McConnell said he was grateful Flake would be with the Senate for another year and a half.

“He is one of the finest human beings I’ve met in politics,” Senate Minority Leader Charles E. Schumer said. “He is moral, upright, and strong and he will be missed by just about everybody in the Senate.”

Flake Gives Anti-Trump Speech on Senate Floor

Flake’s seat was already going to be a tough 2018 contest for Republicans. Election talk stirred even as he spoke on the floor.

“There’s no question in my mind that Arizona is a state that voted for President Trump, it’s a Republican state, and it’s going to be a focus of ours to make sure that it remains that way,” National Republican Senatorial Committee Cory Gardner of Colorado said.

Inside Elections with Nathan L. Gonzales is still listing the race a Tossup.

“The polling looked pretty tough in terms of a re-elect,” Senate Majority Whip John Cornyn of Texas said.

Senate Leadership Fund, a Republican super PAC, responded to Flake’s announcement.

“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 said in a statement.

Arizona voters were the big winners in Flake’s announcement, Ward said in a statement. 

Democrats chimed in too.

“Senator Flake’s retirement is another example of the divisiveness roiling Republican primaries,” a statement from the Democratic Senatorial Campaign Committee said, touting Arizona Rep. Kyrsten Sinema.

White House press secretary Sarah Huckabee Sanders said Flake’s was probably a good move, citing a perceived lack of support from Arizonans.

Bridget Bowman, Eric Garcia, Joe Williams and John T. Bennett contributed to this report.Race Rating Change: Flake’s Arizona Senate Seat Moves to Toss-Up