Greg Brannon, an obstetrician and tea party supporter in North Carolina, kicked off his Senate campaign Wednesday with a two-day tour of the state.

Brannon is the first Republican to announce a challenge to Democratic Sen. Kay Hagan, who is running her first re-election campaign since knocking out then-Sen. Elizabeth Dole in 2008.

Hagan is one of the most vulnerable incumbents this cycle, running in a state that President Barack Obama lost in 2012.  CQ Roll Call rates this race as a Tossup.

What degree of danger Hagan finds herself in will depend partly on the quality of opponent that emerges from next year’s GOP primary. State Speaker Thom Tillis is the most likely to run against her, but other potential candidates include Rep. Renee Ellmers, state Senate President Pro Tem Phil Berger and state Labor Commissioner Cherie Berry — whose face and rhyming name are in every elevator in the state.

Brannon is president of Founders’ Truth, whose goal is “preserving the sacred fire of liberty.” His kickoff tour was scheduled to include events Wednesday in Wilmington, Greenville, Raleigh and Greensboro, and on Thursday in Monroe, Charlotte, Asheville and Burlington.

“As a father and husband, it is clear to me that we must be willing to make the sacrifice and take immediate action to restore our founding principles if we are to preserve the promise of this great nation,” said Brannon, who is from Cary, in a video on his Senate run that was posted to the Founders’ Truth website.