Christie proved that when you speak out, as Perry did, it makes you a target. Your opponents attack you and so do powerful forces like Christie who aren't even in the race. That's what makes candidates tentative, or dooms those that say anything mildly close to honest. This is why Mitch Daniels jokes his campaign might have been over almost before it started. Actually speaking your mind is dangerous.
Christie could announce his campaign and pay no price for reversing his position. Obama said he wasn't going to run before he decided to. Christie could also point to the woman at the Reagan library and the others who have begged him to run and say the groundswell helped him change his mind. Every candidate tries to claim there is a movement of yearning citizens behind calling them to the contest. Christie can roll the videotape. He just has to hope that he lives up to the posture he put forward in his speech or his opponents will roll the videotape too.
Become a fan of John Dickerson on Facebook.