Arizona Republican Sen. Jeff Flake announced Tuesday that he will serve out the remainder of his term but will not seek re-election in 2018.
Flake, who has been an open critic of President Donald Trump, dropped the bombshell in a Tuesday afternoon speech on the Senate floor.
"If I have been critical, it not because I relish criticizing the behavior of the president of the United States," Flake said. "If I have been critical, it is because I believe that it is my obligation to do so, as a matter of duty and conscience."
The senator offered a critique of the state of U.S. politics today:
Mr. President, I rise today to address a matter that has been much on my mind, at a moment when it seems that our democracy is more defined by our discord and our dysfunction than it is by our values and our principles. Let me begin by noting a somewhat obvious point that these offices that we hold are not ours to hold indefinitely. We are not here simply to mark time. Sustained incumbency is certainly not the point of seeking office. And there are times when we must risk our careers in favor of our principles.
The "regular and casual undermining of our democratic norms and ideals" should "never be regarded as normal," Flake said.
We must never meekly accept the daily sundering of our country — the personal attacks, the threats against principles, freedoms, and institutions, the flagrant disregard for truth or decency, the reckless provocations, most often for the pettiest and most personal reasons, reasons having nothing whatsoever to do with the fortunes of the people that we have all been elected to serve.
He said when people succumb to silence and inaction because of political considerations, it's a dishonor to their "principals and obligations."
Flake said he can better serve the people of Arizona, the country, and his conscience by freeing himself "from the political considerations that consume far too much bandwidth and would cause me to compromise far too many principles."
His political fortunes have suffered as a result of his long-running feud with Trump, which included an anti-Trump tome Flake published over the summer, CNN reported. The senator has been struggling in the polls, according to The Arizona Republic.
Former state Sen. Kelli Ward (R), who was challenging Flake for his seat, had turned up the heat against Flake in recent months.
In a campaign ad titled "Arizona Deserves Better," Ward blasted Flake for being featured in a Hillary Clinton campaign ad slamming Trump, Business Insider reported in August.
Flake added he has ruled out running as an independent rather than a Republican, citing that it was not a viable strategy. He also said he has "no intention" of running for president.