What I suspect Romney, Haley, Kasich and Hogan are all doing is planning for one of two contingencies. The first is that Trump resigns or is forced out of office due to one of his many mounting scandals, in which case Vice President Pence will be about as strong as Georgy Malenkov. The second is to wait for someone else to make a kamikaze run at Trump during the 2020 GOP primary, paving the way for a less controversial run at the nomination. This requires an odd game of signaling visibility without moving first. What they all need is the equivalent of a pace car, a politician willing to challenge Trump in such a way as to facilitate more viable entrants. But none of them want to be the one to fall on their sword.

The odds are good that none of these people will ever get past the invisible primary stage. But the most telling sign is that Romney decided to fire this shot in the first place. It is not all about ambition; it is easy to believe that Romney is genuinely appalled by Donald Trump. But tactically, Romney must believe that he is in a comparatively strong position back home, and that Trump himself is a very weak incumbent.