A poll conducted by Harris Interactive has Feingold leading Michels 52 to 39 percent with nine percent undecided.
The poll also shows 35 percent of the 562 residents polled didn't recognize Michels’ name.
Michels is running his first statewide campaign. He had a strong win over three other Republicans in the September primary.
Feingold is running for his third term. Michels is a former Army major who runs a group of construction companies based in Brownsville.
The poll is sponsored by a Madison-based Website, WisPolitics.com.
It has a margin of error of four percentage points.