Tillis accuses Democrats of 'meddling' in GOP primary

Tillis is the front-runner in a field of eight Republican candidates hoping to take on U.S. Sen. Kay Hagan, an incumbent Democrat up for re-election this year. He has produced his own ads to answer the Senate Majority PAC claims.

"Seen those ads attacking Thom Tillis? They're false," says a male narrator. "Tillis fired the staffers. Know who is paying for those sleazy ads? It's Harry Reid. Reid's trying to fool Republican voters, meddling in our primary to get a weak opponent for Kay Hagan."

In order to avoid a runoff election, Tillis needs to earn 40 percent of the vote in the first primary. Otherwise, the second-place finisher can ask for a runoff.

At this point, Dr. Greg Brannon of Cary and Rev. Mark Harris of Charlotte are the most likely second-place finishers. Brannon has used the same Tillis episode in a fundraising mailer. 

While both Harris and Brannon have campaign commercials on television, neither has been able to match the amount Tillis has spent. Plus, Tillis has benefited from super PAC American Crossroads airing commercials on his behalf.

The Senate Majority PAC ads could pick off enough voters to keep Tillis from reaching the 40 percent threshold. 

Democrats responded to Tillis' ad by calling it misleading. Tillis, they said, didn't fire the staffers in question. 

"The truth is, he admitted those two staffers resigned and even used that point to defend the nearly $20,000 in taxpayer money after they were caught having affairs with lobbyists," said Ben Ray, a spokesman for Forward North Carolina, the Democratic political organization working with the Hagan campaign in North Carolina. 

Jordan Shaw, a spokesman for the Tillis campaign, stood by the commercial. 

"The action initiated by Speaker Tillis resulted in the termination of their employment," Shaw said.