Story highlights Tim Stanley: Sen. Jeff Flake vacated the field of battle-- less of a last stand than a tactical retreat, since he was on track to lose primary

Flake's speech betrayed impotence in face of new GOP powered by rage; his walking away concedes he knows Trump isn't going anywhere

Timothy Stanley is a historian and columnist for Britain's Daily Telegraph. He is the author of "Citizen Hollywood: How the Collaboration Between LA and DC Revolutionized American Politics." The opinions expressed in this commentary are his.

(CNN) Since when was it heroic to give up? On Tuesday, Sen. Jeff Flake of Arizona vacated the field of battle by announcing that he won't run for re-election, delivering a remarkable speech in which he attacked the "casual undermining of our democratic norms" and the "coarsening" nature of politics under Donald Trump.

Timothy Stanley

Three Republican senators gave him a standing ovation. Outgoing Sen. Bob Corker accused the President of "debasing" the United States. Flake, he said, is "a real conservative."

But if the choice is that stark -- if Flake really is good and Trump is evil -- why not put that choice to the voters in Arizona? Because polling suggested Flake was on course to lose his primary. This wasn't a last stand. It was a tactical retreat.

There's no disputing that Flake has real disagreement with Trump. A few years ago, he represented the kind of conservative that seemed to be insurgent and on the rise: Western, libertarian, anti-government.

Trump's victory in the 2016 primaries stole the moment from them. If he'd been a little humbler about it, they might have tried to get along with him. But Trump's disregard for constitutional norms departs from the Barry Goldwater tradition of his party, while his name calling and crudity shocked men of religious conscience.