Sen. Jeff Flake (R-Ariz.) wont run for re-election in 2018, The Arizona Republic first reported .

Flake spoke about his decision on the Senate floor Tuesday, railing against the appalling features of our current politics and arguing that lawmakers should never regard as normal the regular and casual undermining of our democratic norms and ideals.

It is time for our complicity and our accommodation of the unacceptable to end, he said.

In a stunning takedown of President Donald Trump , Flake pleaded with his colleagues to respect each other again in an atmosphere of shared facts and shared values and called the presidents behavior outrageous and dangerous to democracy.

I will not be complicit or silent, Flake said. When the next generation asks us, Why didnt you do something? Why didnt you speak up? What are we going to say?