With less than 10 weeks to go until the election, about a third of Wisconsin voters say they don't know enough about incumbent Republican Sen. Ron Johnson to form an opinion of him.
And 25 percent say in the Marquette University Law School poll released Wednesday that they don't know enough about Democrat Russ Feingold to make a decision.
Among registered voters, Feingold had 46 percent compared with 42 percent for Johnson. Among likely voters, Feingold had 48 percent while Johnson had 45 percent.
The poll was conducted Aug. 25 through Sunday, sampling 803 registered Wisconsin voters. It has a margin of error of plus or minus 4.5 percentage points for registered voters, 5 percent for likely voters.