The Senate Majority PAC is spending a reported $750,000 on an ad defending Democratic Sen. Kay Hagan on health care while attacking Tillis, one of five announced GOP candidates for her seat.
The PAC is run by former staffers of the Nevada senator. It's the second pro-Hagan ad they've run in North Carolina.
In it they defend Hagan's support of the Affordable Care Act, without ever referring to the act or to the name its commonly known by, Obamacare. Instead they tout her support of legislation that "forced insurance companies to cover cancer and other pre-existing conditions."
Tillis, it says, "sides with insurance companies."
Tillis tweeted that "It is a badge of honor to be attacked by Harry Reid -- I'll work night and day to beat Kay Hagan and overthrow Reid's majority."
He also emailed a fundraising message to supporters.
"Clearly, North Carolina is ground zero in the effort to get rid of the liberal Reid majority that is keeping Obamacare in place and keeping our country on a path to fiscal disaster," he wrote.