“Christie is clearly making the transition from endorser to enabler and positioning himself to be a major player in the Trump camp,” David Kennedy, a presidential historian, told NJ.com.

Edward Newton, who vetted Christie when he was considered a possible running mate for Mitt Romney in 2012, said the fact that Christie was coaching Trump shows how high his star has risen.

“Leading the debate prep, as Christie has, or the VP candidate search, as Dick Cheney did, fosters a strong relationship and a great level of trust,” Newton said.

“It’s natural for that person to see themselves becoming a potential running mate,” he added about Christie, who was ridiculed for endorsing Trump after bowing out of the race himself.