Vinroot, a former Morehead Scholar and UNC basketball player, was joined for his announcement in Charlotte by fellow candidate Elizabeth Dole, whom he said he will support in her bid to claim the U.S. Senate seat vacated by Jesse Helms.
Vinroot's withdrawal from the race leaves Dole as the only well-known candidate seeking the Republican nomination.
In an interview with The Daily Tar Heel after his announcement, Vinroot said he decided to leave the race after realizing how difficult it would be for him to defeat Dole.
"I'm realistic. I can see how incredibly popular (Dole) is," Vinroot said. "Every poll I've seen has her beating everyone -- Democrat or Republican -- not just me."
Vinroot said he would have a hard time raising enough money to compete with Dole, especially with the nation's declining economic situation.
Vinroot also said his withdrawal from the race leaves the door open for Dole to seize the Republican nomination.
Dole's only remaining competitors on the Republican side are four lesser-known candidates -- Lexington lawyer Jim Snyder, Rowan County Board of Education member Ada Fisher, Lumberton radiologist Jim Parker and Salisbury insurance agent Douglas Sellers.
Democrats who have expressed interest in seeking the post include N.C. Rep. Dan Blue, D-Wake, former White House Chief of Staff Erskine Bowles, Durham council member Cynthia Brown and N.C. Secretary of State Elaine Marshall.
Vinroot said that while he was not nudged to step aside by members of the Republican Party -- as some media outlets have reported -- he has had several conversations in recent weeks with Republican National Committee chairman and Virginia Governor Jim Gillmore about his chances of beating Dole.