Next year's Ohio Senate race is likely to be tough for Republican Rob Portman, no matter who he faces in the general election, a new poll finds.

Rasmussen's early take on the race to fill retiring Sen. George Voinovich's (R-Ohio) seat depicts the former congressman as tied with Democratic Lt. Gov. Lee Fisher. Both poll at about 46 percent among likely voters, with 6 percent of surveyed voters signaling their support for another candidate and 14 percent remaining undecided.

However, Portman does hold a 2-point lead over Jennifer Brunner, the state's Democratic secretary of state. But 18 percent of poll respondents in that matchup said they had not yet made a decision. 

Both numbers illustrate a potential, early problem for Portman, who boasts an impressive resume that ought to do more for his name recognition. The Republican candidate has previously served as director of the Office of Management and Budget and as a U.S. Trade Representative during the Bush administration, not to mention an Ohio congressman from 1993 to 2005. But Portman's popularity remains on par with the state's current elected Democrats -- a concern, considering Republicans have occupied the Senate seat he is chasing since 1998.