What seems to be missing in this conversation is the fact that in America you don't go to jail UNTIL you are convicted of a crime. I certainly understand the sentiment of those who would like to see Clinton in jail but its never going to happen. Even with a special prosecutor chances are he, like Comey, will not find enough evidence, but even if she somehow was indicted there still has to be a trial. She will get the very best defense team money can buy and the trial will probably end up in Washington DC or another favorable venue where the chances of finding her guilty of even jaywalking, beyond a reasonable doubt, are infinitesimal.
Additionally, Trump would be hammered day in and day out for using the power of the Federal government to go after his political enemy and because the Congress will already be looking at the 2018 elections anything that he is trying to get through will stall. Guiliani, Christie and Gingrich simply will not pay the political price of going after her...
Personally, I'd just as soon see him go for it and destroy his Presidency right out of the gate but those who hope to have a political future in the GOP will stop him..