(CNN) -

Sen. Rand Paul on Friday defended his criticism of Hillary Clinton over the 2012 attack against a U.S. consulate in Benghazi, Libya.

The Kentucky Republican, rebutting claims that Benghazi criticism is politically motivated, said Clinton's handling of the attack was a legitimate topic of discussion as she considers a presidential bid.

"There will be discussion over the next four years whether or not Hillary Clinton is fit to lead this country," he said at a Dallas event hosted by the conservative group Americans for Prosperity.

He asked the crowd: "Is Hillary Clinton fit to be commander in chief?"

The audience fired off a robust round of "no's."

The first-term senator went on to compare Benghazi to the 1993 mission in Mogadishu, Somalia, in which 18 U.S. military members were killed. Two months after the tragedy, President Bill Clinton announced the resignation of Les Aspin, then secretary of the defense. Aspin had taken heat for denying security requests for U.S. forces in the region just a month before the attack.

"He ignored the request and he resigned ultimately in disgrace," Paul said. "I think had Hillary Clinton worked for Bill Clinton, she'd probably have been fired."

Paul frequently brings up the former secretary of state, senator and first lady as he lays groundwork for a potential presidential campaign.

In an interview earlier this summer, Hillary Clinton was asked about Paul's attacks, specifically about his claim that President Clinton's affair with Monica Lewinsky could be a liability if Hillary Clinton runs for president.

"He can talk about whatever he wants to talk about," Clinton responded. "And if he decides to run, he'll be fair game too."