Trump didn’t make him AG, yes it’s that petty.
President-Elect Trump fired Christie as manager of his transition team.
The Trump side of the story was that Christie was ineffective and that he filled the transition team with DC lobbyists who were then put in charge of staffing the departments that they were lobbying policies for.
Trump fired Christie and all of the lobbyists from the transition team. He then put Pence in charge of the transition, and Pence then made any incoming registered lobbyists sign agreements to forfeit returning to lobbying for five years after leaving the administration.
The bottom line is that Christie got too incestuous with the lobbyists who were trying to fill the administration with people who supported their policy positions, effectively planting their own insiders into the Trump administration.
That's why Christie hates Trump to this day.
-PJ
Yes, and he was lobbying to be AG.
He still would have been a better choice than Sessions.
Of course, hindsight is 2020.