New Jersey Gov. Chris Christie seldom makes a political miscalculation, as even his adversaries acknowledged after the incumbent Republican rolled to 60 percent of the vote to win re-election in a heavily Democratic state. But when the likely 2016 presidential candidate maneuvered to dump Tom Kean Jr. as state Senate Republican leader two days later, he suffered a rare defeat—and alienated the lawmaker’s father, Tom Kean Sr., a GOP elder statesman and popular former governor who gave Christie his political start. “I’m as surprised as I’ve ever been in my life in politics,” Kean, 78, told The Associated Press. Christie...