Rand Paul made a plea to his fellow libertarian-leaning voters: Don't throw away your vote on a third-party candidate and allow Hillary Clinton to become president.

The Kentucky senator slammed the Clintons at a Rotary Club in Maysville, Ky. on Thursday.

"We have now a comparison between Hillary Clinton and her husband who have grown rich off of government service, selling themselves, and selling their speeches," Paul said. "Bill Clinton made a million dollars talking to a Russian bank that was negotiating the purchase of a uranium company in North America, who had to approve that? Hillary Clinton."

"Bill Clinton made almost a million dollars speaking to an electronics company who was trying to sell electronics into Iran," he continued. "Who had to approve that deal, outside of the sanctions, who had to have a waiver for the sanctions? Hillary Clinton. They ought to be in jail for these things."

While it's understandable that a libertarian wouldn't want to vote for a war hawk and crony capitalist like Clinton, Paul emphasized the importance of voting for Donald Trump instead of Gary Johnson.

Paul said he signed a document giving his word that he'd support the Republican nominee, and urged other voters to support the candidate they agree with the most, even if he's not their first choice.

When it comes to Johnson, Paul said, he's polling well for a Libertarian candidate but it's not realistic to believe he has any chance of winning and a vote for him only helps Clinton, especially in key swing states.

Watch the clips below: