And I imagine that Krugman had to write this piece without the benefit of last night's unbelievable debate in which Rubio and Cruz called Trump a fraud and an idiot and a buffoon and then, when asked whether they would support him if he were the nominee, said, "oh sure."
This isn't a situation where you are saying, "Hey, Joe Blow is an intelligent and honorable man, but we disagree on policy." This is a situation where you are spending 2 hours calling someone a fraud and a con man and then at the end say "but, yes, I am OK with that."
It puts me in mind of the Warner Brothers cartoon where the sheepdog and the wolf are friends who go to work every day and the wolf's job is to steal sheep and the sheepdog's job is to beat the shit out of him. Then at the end of the day they leave and say, "hey, see you tomorrow buddy."