And for Jeff Flake, this could be an opportunity not just to stand up in opposition to Trump, but to actually help bring about his demise. Up until now Flake has been banging his head against the wall, getting a friendly reception from the media for his criticisms of Trump but not actually accomplishing much of anything. A primary challenge, however, would be an entirely different matter.

If Flake ran against Trump, he would get more attention for his ideas than he has ever imagined. He’d be on the news constantly. He might even get a small movement behind him, of traditional conservatives unhappy with Trump for one reason or another. In the best case scenario, Flake could imagine himself as the Republican Bernie Sanders, running a surprisingly successful insurgent campaign of ironclad principle against the choice of the establishment.

That might be a bit of a stretch, especially since Flake is about as establishment as they come. But if he wants to be heard, there’s no better way than running for president.