If you take a shot at the "king"

To be fair, this generally happens in whole or part.

These are part of the Executive Branch by way of the Justice Department.

Clinton, Bush, Reagan etc. have done this.  Trump even did it his first term.

Some have done it in a more blatant way (or retaliatory way) like Bush.  Even Biden threatened to do it to one early on.  I think this is the same one that eventually investigated the documents that Biden 'swiped' while Vice-President.

This time Trump just used it to make a public statement about it.

Geek wisdom:  Always try to do the best job during your first attempt and try to treat it as if it was going to be your last attempt. Because there is a good chance it just may be your only chance to get it right.