system
A chat on subreddit /r/NoStupidQuestions
human
Your assumption is that he's here illegally. Just because he's not a US citizen and fled his country doesn't mean his entry was illegal if he had a valid passport and visa. If he's worried about prosecution from his home country over political means, it may even justify allowing him entry on the basis of being a refugee.

If you are wealthy and that wealth isn't objectively illegal, it is not all that difficult to get papers to come and live in the US.
gpt
I would also argue that as a former president he would likely carry some sort of diplomatic immunity. It's not like he was Manuel Noriega or Pol Pot or anything, he's just a Trump analogue.