It has been suggested that one of the driving reasons he ran for president in the first place was because Barack Obama once roasted him publicly and it was his way of getting even for it. Trump is not one that will sit back and not retaliate if he feels you have wronged him.
Another prime example is how Trump responded to CNN during the campaign after they played the now famous video of him talking about grabbing women by their genitals.
This profile of CNN bigshot Jeff Zucker gives a lot of insight into how Trump operates with vengeance:
For Zucker, the thick-skinned TV executive and newsman, it was just business. For Trump, the thin-skinned TV star and now approval-craving politician, it was tactical but also personal: He believed that he had gotten Zucker his job at CNN and that the network’s increasingly aggressive coverage of him was an act of betrayal.
Trump actually didn’t play a meaningful role in Zucker’s hiring. (“The president is certainly entitled to believe whatever he likes about our conversation,” Kent wrote me in an email, “however, it was not a factor in the decision to hire Jeff.”) But after the second presidential debate in October, when several CNN panelists criticized Trump for dismissing his comments about grabbing women by the genitals as “locker-room talk,” Zucker received an email from Trump, via his campaign spokeswoman, Hope Hicks:
“Jeff — Too bad you (CNN) couldn’t be honest with how well I did in the debate. The dumbest thing I ever did was get you the job at CNN — you are the most disloyal person. Just remember, I always seem to find a way to get even. Best wishes, Donald J. Trump.”
Trump is a revenge-driven person…it’s just who he is.
Remember when President Obama roasted Trump at the White House Correspondents’ Dinner from the stage?
This was almost certainly a factor in Trump decision to eventually run for president. Trump wanted to forced Obama to personally hands him the keys to the Oval Office…and he did.