“What he enjoys most about this job is finding things he has absolute power over,” said one source who’s worked closely with Trump. “He got a kick out of pardons, that he could pardon anybody he wants and people would come to him to court him and beg him.”
Now — after Sen. Rand Paul (R-Ky.) pointed out to Trump that he could revoke security clearances from former senior officials who were attacking him — he is clearly relishing the unilateral power:

For the longest time, according to sources with direct knowledge of the president’s thinking, Trump did not get involved in clearance issues, whatsoever.

He “really wanted to stay out of it, not just for Jared and Ivanka but [for] others,” one source with direct knowledge of the process said.