The former Florida governor was lamenting the state of cybersecurity in the U.S., going through a list of examples where classified information had either been leaked or hacked into.
"Let me see if I can go down memory lane here," he said at a campaign rally here. He mentioned Manning, a former Army intelligence analyst who provided state documents to Wikileaks, and Snowden, a former contractor who exposed classified surveillance programs of the National Security Agency.
"He's not a patriot; he's a traitor to our country," Bush said.
He also decried the recent hacking of the Office of Personnel Management, which authorities believe was carried out by the Chinese government.
"And then you have Hillary Clinton, who was the secretary of state dealing with confidential information, with classified information, thinking it was OK to use a private server? Thinking that her server would be safer than the State Department's firewalls?" he said. "We need a president that recognizes there are threats in the 21st century that are dramatically different than of 30 years ago."
Clinton's campaign did not return a request for comment on Bush's remarks Wednesday. On Tuesday, her spokesman Nick Merrill told CNN that Clinton has "pledged to cooperate with the government's security inquiry, and if there are more questions, we will continue to address them."
Clinton agreed on Tuesday to turn over her private email server
and copies of all work-related emails to the FBI, the same day an intelligence community inspector general told congressional committees that at least five emails from the server contained classified information, though they weren't classified or labeled as such during her tenure at State.
Bush was careful not to directly equate Clinton with the actions of Manning and Snowden, but he forcefully argued that he felt Clinton was being reckless with state information while she led the State Department.
While some Republican presidential candidates have been eager to call for a criminal investigation into Clinton's emails, Bush said he didn't know enough to make such a judgment, but argued that the situation is "disturbing." He questioned why her campaign didn't disclose all of her emails right off the bat, saying, "it looks like she's hiding, the way she's going about this."
"I mean, we got problems with our federal government firewalls obviously, but to have a private server in your home, I mean, come on, man," Bush told reporters. "That doesn't pass the smell test."
Bush, however, has faced criticism of his own over emails. As governor of Florida, he kept a private email account and server, like Clinton.
His aides argue that the servers aren't comparable because his private email was widely known at the time, unlike Clinton's, and that he also used a state email in addition to the private one. And Bush himself has pointed to the thousands of emails that he has voluntarily released
since leaving the governor's office.