Sen. Jeff Flake says he will not run for re-election in 2018

PHOENIX — In a move that turned next year’s Senate race on its head, incumbent Jeff Flake announced Tuesday that he would not seek re-election.

A spokesman for Flake’s office confirmed reports that he planned to leave politics because of the divisive climate created under President Donald Trump.

“There are times at which we must risk our careers in favor of our principles,” he said while announcing his decision on the Senate floor.

Flake’s term will end in early January 2019.

There was no immediate reaction from Trump, but White House press secretary Sarah Huckabee Sanders addressed the decision during her daily briefing.

Trump spox Sarah Sanders on Flake decision not to seek re-election: "It's probably a good move"

— Steve Peoples (@sppeoples) October 24, 2017

The senator and Trump have been at odds since the campaign, a battle that came to a head after he released a book, “Conscience of a Conservative,” in which he bemoaned his party’s failure to stand up to Trump in last year’s presidential race.

“We pretended that the emperor wasn’t naked,” he wrote.

Trump, in turn, has lashed out at the senator on Twitter, calling him “toxic,” while praising Dr. Kelli Ward, who planned to challenge the senator in next year’s primary.

White House officials said there was little chance Trump would have had a change of heart over supporting Flake.

His seat had become a target for both Democrats and Republicans alike. Democratic U.S. Rep. Kyrsten Sinema declared her candidacy last month.

“People are fooling themselves if they think Jeff Flake is anything but a walking dead member of the United State Senate,” said Andy Surabian, whose Great America Alliance is backing Ward.

Ward unsuccessfully challenged Arizona’s senior senator, John McCain, in last year’s election, losing in the primary by a wide margin.

She said Arizona voters would benefit from the senator’s decision.

Arizona voters are the big winner in @JeffFlake's decision to not seek reelection. They deserve a strong, conservative in the Senate 1/2

— Dr. Kelli Ward (@kelliwardaz) October 24, 2017

Who supports @POTUS & the 'America First' agenda. Our campaign proudly offers an optimistic path forward for Arizona & America #MAGA 2/2

— Dr. Kelli Ward (@kelliwardaz) October 24, 2017

Trump reportedly met with other potential candidates — state Treasurer Jeff DeWit and Robert Graham, former chairman of the Arizona Republican Party — for the seat before his August campaign rally at the Phoenix Convention Center.

U.S. Rep. Trent Franks (R-Arizona) was also involved in the meeting, which Politico described as a “backstage huddle.” During the huddle, Trump reportedly referred to Flake as “the flake” and “discussed the potential for a primary challenge to Flake.”

Arizona Gov. Doug Ducey thanked Flake in a statement.

“[Flake] was a voice for fiscal responsibility at the federal level before it was popular, and effectively ended the practice of earmarks,” he said. “I’ve appreciated his friendship, professionalism and intellect on policy issues impacting Arizona. I wish all the best for [Flake], Cheryl and their whole family.”

The Associated Press contributed to this report.

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