PHOENIX (AP) - Arizona Republican Sen. Jeff Flake's re-election race is becoming a case study in the GOP's convulsions between the establishment, a furious base, and angry donors.
 
After bucking Donald Trump in a state the president won, Flake is bottoming out in polls.
 
Yet Republicans look like they may be stuck with a hard-core conservative challenger who some fear could win the primary but lose in the general election.
 
A White House search for a candidate to replace former state Sen. Kelli Ward in the primary appears to have hit a wall. And now conservatives want to turn Arizona into the latest example of a Trump Train outsider taking down a member of the GOP establishment.