As the contentious Republican primary race for U.S. Senate enters its final days, the candidates and independent groups are blanketing the airwaves with millions of dollars in mostly negative ads as part of a final push to sway voters.
A new Marquette University Law School poll released Wednesday shows Tommy Thompson's lead has now shrunk to where it's within the margin of error.
The poll shows Thompson with 28 percent compared with 20 percent for Eric Hovde and 18 percent for Mark Neumann. Jeff Fitzgerald was last at 13 percent while 21 percent are undecided.
The margin of error is 4.4 percentage points.
The poll of 519 likely voters in Tuesday's primary was done between Aug. 2 and Sunday.
Tammy Baldwin is the only Democratic candidate in the race.
A poll by Quinnipiac University, the New York Times and CBS News shows Baldwin running closely against Thompson, Hovde and Neumann. She had a 12-point lead over Fitzgerald.
That poll did not ask voters which of the Republicans they favored.