According to Republican presidential candidate Jeb Bush, Democratic rival Hillary Clinton's greatest weakness is her lack of trustworthiness.

"What's the biggest vulnerability for Hillary Clinton?" Fox News anchor Bret Baier asked in a preview of an interview with Bush that aired Thursday.

"It's her — just this protective shield she wants to create around her candidacy," the former governor of Florida responded. "I just don't think it's going to work."

Clinton simply "can't be trusted," he added. "There is never a straight answer. Whether it's the server, the emails, Benghazi, just constantly validates this notion that there are two sets of rules."

Bush also rejected the idea that potential general matchup of a Bush versus a Clinton would hamper voter turnout.

"I'm going to win the nomination, and I'm going to run a campaign that will inspire people that their lives can get better," he said. "And that'll drive turnout, particularly among people who are conservative and they just don't know it yet."

Numerous polls have echoed Bush's beliefs about Clinton, as they register a feeling of untrustworthiness stemming from her time as secretary of State, including how she handled the 2012 Benghazi attacks as well as her use of a personal email server.

According to a RealClearPolitics average of polls, Bush solidly leads the Republican field for the nomination, but not by the huge margin that Clinton enjoys among Democrats.