LA CROSSE, Wis. -- Wisconsinites will head to the voting booths next Tuesday to cast their ballots in the August primary.

That means picking which Republican they want to see face off against Democrat Tammy Baldwin for the open U.S. Senate seat.

The four-person race has turned out to be much closer than expected.

And according to the most recent poll by Public Policy Polling (PPP), it’s anyone’s game. The poll, released on July 31, shows businessman Eric Hovde at the head of the pack with 28 percent of likely Republican voters. Tommy Thompson and Mark Neumann are tied at 25 percent. Jeff Fitzgerald polled at 13 percent.

Hovde's lead may be the biggest surprise about this poll. He was a political unknown before throwing his hat in the ring.

"We have to put people in Washington, D.C. that are going to put their country first instead of their political careers. And I'm a private sector person that just got tired of yelling at the television set every day and concerned about the direction our country is heading," said Hovde.

Former Gov. Tommy Thompson is hoping his name recognition will help him next week.

“People know me. Eighty-eight percent of the people in the state of Wisconsin know me. I'm the only candidate -- and I think this is true -- of any place in the United States, Democrat or Republican, that can run statewide and just use my first name, Tommy," said Thompson.

Thompson is neck-and-neck in the PPP poll with Neumann, who's billing himself as the most conservative candidate in the race.

"Well, I think that the Tea Party Express endorsement that we're here enjoying a rally with this afternoon is an indication I am the most conservative. Conservative, to me, means has a plan to balance the federal budget, has a plan to cut spending, has a plan to repeal Obamacare, and actually our plan goes the next step and shows how to pay off the federal debt as well," said Neumann.

After a fundraiser in La Crosse Tuesday morning, Thompson accused Hovde of “ trying to buy this election.”

Here's a look at the amount of money the GOP candidates have raised so far, according to OpenSecrets.org:

Money Raised by GOP Senate Candidates
Eric Hovde - $5,532,185
Mark Neumann - $2,728,227
Tommy Thompson - $2,463,064
Jeff Fitzgerald - $144,455

Their Democratic challenger, Tammy Baldwin, has raised $7,106,187.

Hovde is putting some of his own money into his campaign, but refuses to disclose how much.

But as the GOP candidates spend the next week talking about why they think they can beat Democrat Tammy Baldwin, goal number one is just to get Republican voters to the voting booth in the first place.

"I think it's going to be a small voter turnout. And that's why every vote is important. And that's why this morning, we stress the fact that people need to go to the polls and vote," said Thomspon.

A new Marquette Law School poll is expected to come out on Wednesday.

The primary is Tuesday, Aug. 14.