Neumann has ramped up his television presence in the last few weeks, and the Club for Growth has come to his aid by running ads bashing Thompson and Hovde. He also won the endorsement of the Tea Party Express this week. Fitzgerald has generally remained above the fray and allowed the other three candidates to bloody each other. Despite his anemic fundraising, Fitzgerald went on air with his first television spot earlier this week, and he benefits from his association with Gov. Scott Walker, who remains very popular among Badger State Republicans. Fitzgerald helped shepherd Walker's agenda through the state legislature during the contentious 2011 session. Despite Thompson's significant early advantages, many Wisconsin GOP strategists have expected the former governor's lead to disappear as the other contenders became more well-known and voters paid closer attention. Hovde emerged this summer as the most likely alternative, thanks to millions of dollars in personal money spent blanketing the state in television ads. But the late surge of Neumann and, to a lesser extent, Fitzgerald, has splintered the anti-Thompson vote. Among all voters, the steady onslaught of negative campaign ads has taken its toll on the leading Republican candidates. The new poll shows a spike in the negatives for Thompson, Hovde and Neumann. Thirty-nine percent of registered voters said they have a favorable view of Thompson, while 43 percent said they have an unfavorable view of the former governor. In July, 36 percent said they viewed Thompson unfavorably. Hovde's unfavorable number jumped 13 points in the new poll, while Neumann's increased by 11 points. The poll, which was conducted August 2 through August 5, surveyed 1,400 registered voters and carries a margin of error of plus-or-minus 2.6 percentage points. The subsample of 1,188 likely general election voters has margin of error of plus-or-minus 2.8 percentage points, while the subsample of 519 likely Republican primary voters has a margin of error of plus-or-minus 4.3 percentage points. The Republican primary is August 14.