(Image Credit: AP Photos)

ABC News' Michael Falcone reports:

GREEN BAY, Wisc. - As they prepare to head to the polls to help select the Republican presidential nominee, many Wisconsin voters have had it with the GOP primary.

In a series of interviews with ABC News in all corners of the state, which is holding its nominating contest on Tuesday, these voters expressed a similar message: enough already!

At a Friday night fish fry at the American Serb Hall in Milwaukee, Paul Seifert, a physician from Waukesha, Wisc., said he had decided to support Mitt Romney because "he's the only one who can beat Obama."

"I very much hope that he gets the nomination and we get this thing settled soon. These guys are kind of tearing each other apart in the process," Seifert said.  "I think it's a circular firing squad at this point. I think that Newt Gingrich and Ron Paul have no chance. Rick Santorum's got a very slim chance."

Thirty-two states and territories have already held primaries or caucuses and voters in another 21 states and the District of Columbia will have their say between now and the end of June. But here in Wisconsin Republicans like Seifert, who are singularly focused on replacing the president, believe that this year's GOP nominating contest has dragged on long enough.

The sentiment comes at a time when Romney is attempting to shift his focus from Rick Santorum, one of three remaining opponents, to the coming battle with President Obama. Romney's commanding delegate lead is likely to grow even larger after Tuesday.

Santorum, on the other hand, is not ready to give up. As recently as Monday, he told reporters at an Appleton, Wisc. cheese shop that, "in this primary, the longer it goes the better it is for the party."

But Former Wisconsin Gov. Tommy Thompson, who is running for a U.S. Senate seat and has not endorsed a presidential candidate, said in an interview with ABC News that he and his fellow Wisconsinites were ready to move on.

"People want the primary over, they want to get on with it. They're saying, 'enough's enough. Romney is not everything everybody really wants, but he's got the best chance against Obama,'" Thompson said, noting that his assessment of Romney reflected the prevailing sentiment among voters, not necessarily his own view.

"We're done with the preliminary bouts and now it's time for the main event," Thompson said at a Waukesha County GOP Lincoln Day dinner on Saturday, "and that's Romney and Obama."

Many Wisconsin voters, who have been beset by a prolonged political drama in their own state where Republican Gov. Scott Walker is facing a June recall election, agreed.

"If it continues on, it's actually detrimental. It's actually going to be worse," said Michael Best of Pewaukee, Wisc., who said he was undecided but leaning toward Romney. "We need to focus and pick one candidate right now and then move with that one candidate forward."

Not surprisingly, some Santorum supporters suggested there were reasons to carry on.

David Matasek of Mequon, Wisc., who attended a gathering of the state's socially conservative Faith and Freedom Coalition on Saturday morning outside Milwaukee, warned that "the establishment and the media is feeding us a story that says this needs to be over."

"Here's what I believe," Matasek said. "I believe very strongly that this is a process to vet the nominee."

But even among voters here who have yet to make up their minds, the general election is beginning to loom large.

Ed Butte of Pewaukee, Wisc., another undecided voter who stopped by a Sunday morning pancake breakfast to listen to Romney, said the economy and electability were his top concerns.

"The sooner we can get on to focusing on the real issues and bringing those to the American public as opposed to just constant back and forth fighting will be beneficial for the long term," Butte  said. "Things are starting to align, so let's make a decision, let's move forward and get on with it."