Chris Christie may have the aspect of William Howard Taft, but he has the manner of Teddy Roosevelt — tough, tenacious, tireless. Christie is naturally and constantly on the offensive. When he takes off his jacket at a town hall meeting, someone is in for a rough ride. But his most exceptional political skill is not confrontation but explanation — educating voters in the grim realities of state budgeting, public pensions, unfunded liabilities and teacher union obstructionism. He is both pugilist and professor — a good vice presidential combination.

Christie would not transform New Jersey into a presidential swing state — a persistent but hopeless Republican dream. But he could contribute to the repositioning of the Romney campaign in two important, seemingly contradictory ways. Christie would provide an infusion of blue-collar combativeness, which is foreign to Romney and pleasing to GOP conservatives. At the same time, Christie would represent a move to the ideological center. He is not a global warming skeptic. He supported an assault weapons ban in his state. He is an immigration moderate and has friendly relations with New Jersey’s Muslim community.