New RNC Ad Ahead of Debate: Hillary Clinton 'Not Telling Us the Truth - Again' (VIDEO)

RNC pounces on the Clinton emails

Republicans are pre-butting Hillary Clinton ahead of Tuesday night's Democratic debate with a new advertisement that accuses her of misleading the public by using a private email server during her tenure as secretary of state.

The ad, paid for by the Republican National Committee, highlights Clinton's comment that she "did not email classified material to anyone." Hundreds of her emails have been retroactively classified, though, as U.S. agencies have reviewed their contents before their release.

"Hillary Clinton is not telling us the truth ... again," the ad says in text displayed on screen.

The five-figure ad buy will put the 30-second spot on cable television and online -- where it will be specifically targeted toward supporters of Vermont Sen. Bernie Sanders, Clinton's toughest primary opponent thus far