She's already been investigated, over a year and a half on just the emails, and another 3 years With all the Benghazi investigations, and nothing that reached a CRIMINAL level was found, as per the FBI and Congress critters with their 8 investigations.
If Trump cronies go after her again, and once again have nothing criminal, then it will SHOW that he and his ilk, lied through their teeth, during the run for the election. It will also show, that he and his Republican establishment ilk USED our law enforcement services to simply attack a political opponent, which is what dictators and minions do to their opponents.
And lastly, Trump knows if his team continues with this unethical behavior of using tools in Justice system for going after opponents, then he will know that the same measures WILL BE DONE towards him by the Democrats in congress, investigating him for every wrong and idiotic move he makes....and the Dems simply have to say to him and the R's in a language Donald totally understands, ''YOU STARTED IT''!