Incumbent Senator Russ Feingold is supported by 51% of Wisconsin residents in an early poll, according to Graeme Zielinski

By 51% to 29%, residents polled in March said they would like to see Feingold re-elected for his third term, with the remainder not answering the question or saying they didn’t know.
In a separate question, 47% said they had a favorable impression of Feingold, while 19% said their view was unfavorable, figures that have stayed relatively constant since fall. About a third said they didn’t know enough to have formed an impression.
Meanwhile, Feingold’s Republican rivals remained largely unknown, with neither state Sen. Bob Welch (R-Redgranite), construction executive Tim Michels or car dealer Russ Darrow registering with more than one in five residents.