Remember, he couldn't even get Clinton after she deleted 30K mails out of evidence.
That's because emails aren't used for sensitive government communications, because it's the most unsecure form of communication in the world. In the business world, people give access to their business email accounts to secretaries, assistants and other staff, who may or may not have clearance. It's also highly hackable, especially microsoft email programs.
Yet by Comey's own admission, they found plenty of sensitive mail, and also classified mail on her server.
Not to mention the casual yoga mails, that were so secret that they had to be bleach bitted.
So Trey Gowdy seized on her private email server, which Republicans had known about since 2008, and made a big deal over it. It was a nothing burger and Republicans knew about it.
Republicans were aware that Clinton was using a private email server from the moment she took office. And said nothing. Colin Powell told Hillary to use a private server - he did. No one cared for 8 years, until the Republicans could find nothing in Benghazi, Benghazi, Benghazi to go after her for after 7 investigations.
The "classified" materials on her server were the times and dates of government meetings. Nothing essential to national security. And none of her emails fell into the wrong hands. The whole email investigation was the very definition of a "witch hunt".
And fools like you still think it matters, even though the Trumps have a private server in the White House and Ivanka has used private email, for government business which is NOW ILLEGAL.