It seems as if it happened sometime in the last century, but it was really just four years ago. On November 5, 2013, Chris Christie was reelected as governor of New Jersey in a landslide of epic proportions. The Republican’s 60.3 percent of the vote in what had become a deep blue state was a ringing affirmation of the policies he pursued in his first term and, for at least a couple of months, made Christie seem as if he was a serious contender for the presidency in 2016.

But as voters went to the polls today to choose his successor, Christie’s running mate in 2013, Lieutenant Governor Kim Guadagno was headed to certain defeat largely because of her association with the incumbent. Christie’s approval rating in the latest Suffolk University poll is 14 percent, with 77 percent viewing him negatively, numbers that make him among the most unpopular American governors in recent memory.

The answer as to how this reversal of fortune came about is generally summed up in one word: Bridgegate. The scandal in which members of the governor’s staff created a days-long traffic jam on the George Washington Bridge as a way of retaliating against the mayor of Fort Lee, N.J., was first revealed only a month after Christie’s reelection and the governor’s reputation never recovered from the blow. Rather than a triumphant platform from which he would move effortlessly onto the national political stage, his second term was a nightmare that was plagued by investigations into the scandal and a futile presidential run that ended in humiliation.