Definition: In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Input: Washington (CNN) Republican Sen. Jeff Flake of Arizona, a frequent critic of President Donald Trump, will not run for re-election, he said Tuesday in a blistering speech on the Senate floor that bemoaned the "coarsening" tenor of politics in the United States. Flake denounced the "complicity" of his own party in what he called an "alarming and dangerous state of affairs" under Trump, blaming the President for setting the tone. In his speech, Flake assailed a "flagrant disregard for truth or decency" and attacked a "regular and casual undermining of our democratic norms." "When such behavior emanates from the top of our government, it is something else: It is dangerous to a democracy," Flake said.Sen. Jeff Flake, a Republican, has long feuded with President Donald TrumpFlake faced a GOP primary challenger next year and a tough re-election fight 
 Question:"One of the greatest people I've served with," Corker said after the speech, describing _ and adding later, "He's what I would call a real conservative."

Jeff Flake