A political science professor at the University of South Florida Sarasota-Manatee, O'Brien in 2009 lost a city council race to incumbent Patrick Roff by a margin of 52 percent to 48 percent.
O'Brien joins three other announced candidates for the mayor's seat in Bradenton: incumbent Wayne Poston; city council member Marianne Barnebey; and Travis Holliday.
O'Brien, who has worked with several local nonprofits, declined to comment, saying he would be officially kicking off his campaign with an event at noon Wednesday outside Bradenton City Hall -- complete with an official campaign double decker bus.
The ballot for Nov. 6 election will be set at noon Friday, when the candidate qualifying period ends.
Political Watch is keeping a closer eye on local and state government and on politics, from a Manatee County perspective. Marc R. Masferrer is metro/online editor for the Bradenton Herald. Follow him on Twitter @MRMasferrer or email:email@example.com