Rasmussen reports:

The latest Rasmussen Reports telephone survey of likely voters in Ohio finds Republican Rob Portman still slightly ahead of his two chief Democratic rivals, Lieutenant Governor Lee Fisher and Secretary of State Jennifer Brunner. The battle is over the seat now held by retiring GOP Senator George Voinovich. Portman leads Fisher 43% to 38%, with 14% of voters still undecided. Four percent (4%) prefer some other candidate. The former GOP congressman posts a 45% to 38% lead over Brunner. Again, four percent (4%) like another candidate, while 13% are undecided.

The Real Clear Politics average of polls has Portman leading Brunner and Fisher by two points.