MADISON, Wis. - 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.
THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.
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.
Federal election spending reports show that through July, all four Republican candidates spent about $9.6 million while third party independent groups have contributed about $3.8 million. Most of that, more than $2 million, has poured in since July 24.
The Republicans are former Gov. Tommy Thompson, former U.S. Rep. Mark Neumann, hedge fund manager Eric Hovde and state Assembly Speaker Jeff Fitzgerald.
The winner of Tuesday's primary will advance to face Democratic U.S. Rep. Tammy Baldwin on Nov. 6. She is running unopposed on the Democratic side.
The Senate seat is open due to the retirement of Herb Kohl, a Democrat. Republicans haven't held the seat since 1957, which was also the last time they were in control of both Wisconsin Senate seats.
Tea party Republican Ron Johnson, who won the state's other seat in 2010, declined to endorse any of the candidates Tuesday. Gov. Scott Walker, fresh off his June recall election victory, has also declined to endorse anyone.
Two polls released Wednesday shed light on the state of the race less than a week before the election.
The poll by Quinnipiac University, the New York Times and CBS News did not ask voters which of the Republicans they favored. Instead, it focused on how Baldwin would do against each of the Republicans.
In a head-to-head competition, Baldwin and Thompson each had 47 percent. Baldwin led Hovde 47 percent to 43 percent and she led Neumann 48 percent to 45 percent, both of which were within the poll's margin of error. She had a 12-point lead over Fitzgerald, 51 percent to 39 percent.
The poll conducted from July 31 through Monday of 1,428 likely voters had a margin of error of plus or minus 2.6 percentage points.
A Marquette University Law School poll to be released Wednesday showed how the Republican candidates were doing against one another heading into the primary.
Thompson, who hasn't been on the ballot in Wisconsin since 1998, entered the race hoping he would be unchallenged. But Hovde, a hedge fund manager who made millions during 24 years in Washington, D.C., launched his first campaign and proceeded to pour more than $4.8 million of his own money into the race.
Even though Thompson and Neumann are also millionaires, Federal Election Commission reports show that through July, Neumann hadn't spent any of his own money and Thompson had put it only $32,500.
Fitzgerald, a champion of Walker's conservative reforms in the Legislature, has consistently lagged in the polls and fundraising.
Based on the latest FEC reports, Hovde has spent $4.9 million on the race, Neumann has put in $2.5 million, Thompson has spent $2.1 million and Fitzgerald has spent $115,000.