MADISON, Wis. — Even with the biggest name in modern Wisconsin politics, the Republican primary in a highly competitive U.S. Senate race appears headed for a fractious four-way battle Tuesday. Many election-weary voters simply haven't made up their minds.
Tommy G. Thompson, the former governor and Cabinet secretary, has near universal name recognition in the race to succeed retiring Democratic Sen. Herb Kohl. A recent poll finds Mr. Thompson leading the GOP field, but nearly 1 in 5 voters hasn't settled on a nominee.
Mr. Thompson had expected an uncontested run for the nomination, given that his history with the party dates to his first election victory in 1966 and includes 14 years as governor. He also served as health and human services secretary under President George W. Bush. But the party has become more conservative since he left the governorship in 2001, and his three challengers argue they are more in touch with modern Republicans than the 70-year-old Mr. Thompson.
The campaigns are spending millions on television ads trying to sway undecided voters, and each candidate seems to appeal to a slightly different constituency. Mr. Thompson is the experienced workhorse with the most political ties. Former U.S. Rep. Mark Neumann is the tea party favorite. Eric Hovde is the political newcomer who made millions as a businessman. And Assembly Speaker Jeff Fitzgerald has the most direct ties to Gov. Scott Walker, who survived a high-profile recall election just two months ago.
One theory is that Wisconsin is enduring a political hangover after that recall election, which Democrats organized as payback for Mr. Walker's push to strip most public employees of nearly all their collective-bargaining rights. And, the primary is a month sooner in order to comply with federal law. The result: Only 20 percent turnout is predicted.
"Wisconsin has been the state of chaos, and I think people needed a break after the recall election and just weren't paying attention, unfortunately," said Nancy Milholland, a co-organizer of the Racine Tea Party. "All of our time spent working and focusing on the recall election would have been directed at the United States Senate race. The recall sucked the air out of the room."
The winner of the Republican race will take on Democratic U.S. Rep. Tammy Baldwin, who is uncontested. No Republican has held the seat since 1957 — the demagogic Sen. Joseph McCarthy of "McCarthyism" infamy — but the GOP sees it as an opportunity as they try to wrest majority control from the Democrats.
Keith Best, a salesman from the Republican stronghold of Waukesha, acknowledges that the recall took attention away from the primary but says he's undecided because all four candidates are strong.
"I probably won't make up my mind until I walk into the poll that Tuesday," Mr. Best said. "Game day decision."