Republican Senator Jeff Flake of Arizona, who has sparred frequently with President Donald Trump, will not run for re-election, he said Tuesday.

"The notion that one should stay silent as the norms and values that keep America strong are undermined and as the alliances and agreements that ensure the stability of the entire world are routinely threatened by the level of thought that goes into 140 characters -- the notion that one should say and do nothing in the face of such mercurial behavior is ahistoric and, I believe, profoundly misguided,” Flake said, according to CNN.