Lesson #3: Chris Christie Is A Legitimate Threat.

If Romney’s exit doesn’t really help Bush, it helps Chris Christie enormously. In fact, right after his tweak of Jeb, Mitt Romney headed to a dinner with the “fresh face” he apparently had in mind: the New Jersey governor. Many would-be Romney donors are reportedly following his lead.

Should he enter the race, the Christie campaign strategy is not a mystery: To let everyone take whacks at Bush while Christie clings to the most valuable quality in all of presidential politics: being underestimated. The New Jersey governor shares many of Jeb Bush’s strengths: experience running a complicated, politically diverse state; an appeal to moderates; and with his proximity to New York, ready access to big-dollar donors. But he also has a few traits that seem to be notably absent from the third would-be President Bush: a crackling speaking style and a reputation for ruthlessness. One has the sense that when an opponent differs with Bush, he responds with a handwritten note and carefully reasoned arguments. When an opponent crosses Christie, he is more likely to receive a flurry of New Jersey-spawned expletives, a couple of “you’re dead to mes,” and the business end of a baseball bat. In other words, if Moderate-ville is looking for a new sheriff, their choice is Andy Griffith or Judge Dredd.