Chris Christie’s job approval is at a career low.

Nearly three-quarters of New Jersey voters, and half his fellow Republicans, said in a recent poll that he should have been a defendant in the trial over the George Washington Bridge lane closings, in which two of his former aides were convicted last month.

And in a stinging turnabout, Bill Stepien, the campaign manager whom Mr. Christie dismissed in the so-called Bridgegate scandal, is expected to become Donald J. Trump’s White House political director, while Mr. Christie was fired as transition chief and shut out of jobs in Mr. Trump’s administration, despite having been one of his earliest big-name supporters.

Welcome home, Governor.

“Governor Christie has been abandoned by virtually everyone,” Krista Jenkins, director of the Fairleigh Dickinson University PublicMind Poll, said when the findings showing his approval rating at 18 percent were released this month.

Once considered the Republican Party’s best hope to win the White House, Mr. Christie has endured months of humiliation after he dropped out of the presidential race and endorsed Mr. Trump — who mocked him as they campaigned together for eating too many Oreos, and passed him over as the vice-presidential nominee. Now, Mr. Christie has returned to New Jersey a lame duck in his last year to discover voters angry over his absences and a Legislature suddenly unwilling to go along with his agenda.