OSHKOSH, Wis. — Three months after the primaries started, Republicans in Wisconsin are glad to see the presidential campaign last long enough to reach them. And then they want it to be done, the quicker the better.

Around the state, many Republicans approach Tuesday’s Wisconsin primary with a sense of inevitability that Mitt Romney will win the Republican nomination. They think the often nasty primary campaign is hurting the party. And they feel it’s time for rivals Rick Santorum, Newt Gingrich and Ron Paul to fold up and rally for a fall campaign against President Barack Obama.

The sentiment among rank and file voters suggests a turning point in the campaign where Romney could start to take the nomination more for granted — though he cannot clinch the delegates needed for many more weeks — and turn more and more to challenging Obama.

“It’s really exciting. We have a chance to be a player in the nomination,” said David Richards, a plumber from Oshkosh who plans to vote for Romney.

Yet Richards is one of many who fears the campaign has gone on long enough, maybe too long already. “It’s detrimental to the party. It’s bitter and divisive, tearing down one another. The candidates without a chance should pull away and support the candidate who’s going to win.”

It’s not just Romney supporters.

Mike Donnelly, a retiree from Neenah, plans to vote Tuesday for Santorum. Then, he said, it’s time to rally around Romney.

“I’m for Santorum. But I don’t think he’s going to win. Romney’s going to win,” he said. “Enough’s enough. Let’s pick a candidate and go after Obama.”

Wisconsin is the biggest and most contested prize of the voting Tuesday, with 42 delegates at stake. Maryland has 37 delegates; Washington, D.C., has 16. Romney leads among delegates needed to win the Republican nomination, and is expected to add to that lead on Tuesday.

Wisconsin looks a lot like other big Midwest industrial states where Romney has won, such as Illinois, Michigan and Ohio. And it doesn’t have the large numbers of evangelical Christians that have helped Santorum win in such states as Alabama and Mississippi.

Even at a gathering of religious conservatives from the western suburbs of Milwaukee, Wisconsin voters were a little wary of Santorum’s more open embrace of issues such as abortion and marriage, not to mention his criticism of John F. Kennedy for promoting the separation of church and state when he ran in 1960.

“I go to church every week. I do want God back in the Constitution,” said Dave Barkei, a retired engineer from East Troy. “But he may be too religious. He makes me nervous. There still needs to be some separation between church and state.”