Mr. McAuliffe broke a 36-year pattern in which Virginia’s governor, picked the year after the presidential election, came from the party out of power in the White House. The political scientist who first remarked on the trend, Larry J. Sabato of the University of Virginia, ascribed it to a natural tendency toward buyer’s remorse. But this year, as unpopular as Mr. Obama and his health care law may be with many Virginians, “dislike of Cuccinelli is even stronger,” Mr. Sabato said.