We all know that Donald Trump projects. He knows that he should be locked up
When Trump says that it looked like Hillary Clinton was on some kind of drug during the last debate, he is describing himself. When Trump says Bill Clinton is a sexual predator, he is describing himself. When Trump claims that Hillary Clinton sexually assaults women, or course he is describing himself. And when Donald Trump says that Hillary Clinton believes that she is entitled to special legal treatment, again he is describing himself. Trump says Hillary should be locked up now because he knows there is ample cause for himself to now be imprisoned now; either for sex crimes or for tax fraud.
I think a lot of the impetus behind Trump constantly screaming that the system is rigged against him now is a threat, that he will bring it down violently if anyone moves against him legally. When Trump claims that Hillary should be locked up already, he is laying the groundwork for civil unrest if "the system" ever tries to lay a legal hand on him after Hillary allegedly "got away" with criminal behavior for years. It would become proof that the system is out to get him ad him alone
Trump is the one seeking legal amnesty, another of his pet "projection" issues. His goal is to make it too dangerous for any prosecutors to accuse him of any crimes. When Trump says that the current Administration called off the Justice Department from prosecuting Hillary Clinton for "political reasons", he is telling the next Administration to call off the IRS from prosecuting him for a chilling political reason - Trump will incite rioting and violence if he is legally held to account for his actions. He wants a free pass and he is willing to rig the mind set of his core followers to "spontaneously" rebel if anyone threatens to lay a hand on him.