Grasping Reality on TypePad, by Brad DeLong

...For this race to play out like the last one did would require... 1) That the establishmentarian field winnows sooner than later.... 2) Trump fades. Trump does not appear to be an extinguishable threat, the way Perry, Cain, and Gingrich were. Trump might have hit his ceiling, but there’s nothing in the offing right now that promises to drag him back down. If Ben Carson surges, that’s not going to be at Trump’s expense. It will be at the expense of the rest of the field. 3) As conservative also-rans drop out, their supporters break for establishment candidates, rather than for Trump. This seemed plausible earlier in the race, but Trump is now not only leading the field, but he’s also polling well as a second-choice candidate.... Short of sabotaging Trump by changing the rules in the middle of the race, which would risk driving him to mount an independent candidacy, the race itself will have to take on a completely new character for Trump to lose steam. Otherwise, he will win.