Mrs. Clinton, former Secretary of State and formerly known as the Smartest Woman in the World, has neither the need for classified information, nor the mental aptitude necessary to even recognize it, from Daily Caller [1]:
President Donald Trump is considering revoking the security clearances of former CIA Director John Brennan; Comey; former Director of National Intelligence James Clapper; former Director of National Security Michael Haden; former National Security Adviser Susan Rice; and former FBI Deputy Director Andrew McCabe
[…]
“There is more than ample evidence that Hillary Clinton committed, whether its gross negligence, or, as [former FBI Director James] Comey would like to say, extreme carelessness,” Williamson told TheDCNF. “Just from the documented evidence, there was enough to prosecute. If there’s evidence to prosecute, then there’s certainly grounds to pull somebody’s clearance.”
Being shown to be grossly negligent, is ample reason to revoke Mrs. Clinton’s clearance.