Hillary was Sec of State. The FBI has always tried to tell the Sec of State what to do but sometimes the restraints are too much for diplomacy, secrets need to be shared with allies and plain talk is sometimes necessary. Hillary would know when these situations arise, Trump would not. Her email was not as private as some would believe, she still used a heavily secured phone and server. Any server can be hacked.
If Barr starts looking at use of email servers, he will have to look at Jared and Ivanka.
This is the double-standard that Americans allow, if someone is in high political office, or CEO of a bank, no one can touch them, unless they do something against the establishment. This is why we need a revolution, not another democrat or republican, they are both wings off of the same fowl bird.