Yeah, I love this...
b/c those of us who paid attention in civics class know that it's not the President's job or preview to prosecute anybody. That's the role of the Judicial branch, of which he is not in charge.
So when he promises to prosecute her, what he's saying is, either (1) I don't know civics law, (2) I will do something unconstitutional, or (3) I try to coerce somebody in another branch to do what I want, and I'm convinced I'm so awesome at this I can just promise now that it will happen.
None of those seems very appealing.
Remember how just a week ago everybody was pissed that the FBI Director gave a somewhat strong "recombination" on what the JD should do, and everybody got all pissy that he shouldn't be doing that?
a lot of people see that as a good thing - but there's a difference between not being a career politician, and at least knowing enough basic civics to know what the powers and responsibilities of each branch are...