It doesn't matter if Chris Christie DID close bridge lanes to punish political opponents. And it doesn't matter if he knew that one of his underlings did. That's just a question of fact, and facts don't matter.
matters? People believe Christie is the kind of guy who WOULD do that. It's shorthand for the whole persona, and it's the kind of persona that mere facts can't rebut.
People don't want a mean president. They want a TOUGH president. Mean is small. Mean is petty. A tough president negotiates with Putin or kills bin Laden. A mean president worries about getting payback on political enemies. Wrong. That's what you hire Rahm Emanuel or your brother Bobby for.
Scott Walker is mean. His first priority was payback against rivals, specifically labor. But he spun it as tough and he stayed just barely inside the rules, even though he broke a lot of unwritten ones. Look for him to inherit the establishment front runner label soon.