The fundraiser was a closed event, but on the list of attendees was Karl Rove, the Republican strategist who worked with President George W. Bush.
The fundraiser was just days after Vice President Joe Biden was in town for Tillis' opponent, Sen. Kay Hagan.
The election is next fall, but the GOP camp has already been attacking Hagan's support of the Affordable Care Act with negative political ads.
Hagan has said she is helping to work on a solution.
Republicans hope the anger over Obamacare and people losing their insurance policies will pave the way for Republican control in the Senate and possibly smooth over their role in the government shutdown.
Rove is scheduled to make three stops in North Carolina for Tillis. The next two stops are in Fayetteville and Charlotte.