Paul was the keynote speaker at the Mackinac Republican Leadership Conference, and won the unofficial poll with 36 percent of the vote.
"We're pretty excited about it," Paul said. "We've had a great reception here and a lot of enthusiasm and we're excited about winning the poll so many years out."
New Jersey Gov. Chris Christie came in second with 16 percent. The Detroit News reported.
Paul and Christie have recently had disagreements over national security and spending issues, the News said.
The conference attendees also cast votes for lieutenant governor, the Detroit Free Press said.
Current Lt. Gov. Brian Calley won the poll, and beat out his potential Tea Party challenger, Wes Nakagiri.
Calley won 86 percent of the votes, and Nakagiri won 14 percent.
Millions of Getty images now available for free via embed tool
Aaron Carter is still in love with Hilary Duff