HUDSON, Wis. — The stacks of campaign lawn signs at political party headquarters in this western Wisconsin city are being readied to go: Donald Trump for the Republicans and Joe Biden for the Democrats.

Already considered a presidential swing state in recent elections — one that Trump and Biden have each won by little more than 20,000 votes — Minnesota’s neighbor to the east is considered one of just a handful of battleground states in the 2024 presidential election.

Very soon, it will feel like it, party leaders say. On Tuesday, Wisconsin voters head to the polls to cast ballots in the all-but-decided presidential primary, plus local races and referenda and two state constitution questions.

Then the parties turn their attention to national and state issues that will dominate the discussion until November.

“I think there’s gonna be a lot of money spent,” St. Croix County Democratic Party Chair Paul Hambleton said of the expected political ads, mailers and other get-out-the vote efforts.

County Republican Chair Matthew Rust agreed. In the second showdown between Trump and Biden, he said, “a lot of people are thinking Wisconsin could be the one that actually determines for sure.”

Of course, a presidential election is fought and won in every state in the country. But from a technical standpoint, whether Biden or Trump wins the presidency will likely to come down to just a few truly in play in the Electoral College.

Wisconsin is one of just four states listed as toss-ups by Sabato’s Crystal Ball, the nonpartisan newsletter from the University of Virginia’s Center for Politics. The others are Arizona, Georgia and Nevada.

“At the presidential level, it’s one of, if not, the most important,” said Kyle Kondik, the newsletter’s managing editor. “In terms of what state is likeliest to vote for the winning presidential candidate, Wisconsin has got to be — if it’s not the top state on the list, it’s one of the top few.”

Wisconsin isn’t just a linchpin in this year’s presidential campaign, it’s also key to the U.S. Senate, which Democrats hold by a narrow margin, Kondik said. Sen. Tammy Baldwin, a Democrat, is running for re-election against Republican challenger Eric Hovde in a race that will amplify the national attention paid to Wisconsin voters.

Some of that attention will likely come to every corner of Wisconsin, Kondik said, including the largely rural areas closest to Minnesota.

Minnesota is not thought to be as competitive in November’s presidential race as Wisconsin. While Trump came closer to winning Minnesota in 2016 than any Republican in decades, Biden won the state four years ago by more than 230,000 votes — 11 times his Wisconsin margin.

Part of the difference comes down to where the two states’ votes lie. While the metro areas make up large masses of both states’ voters, Wisconsin’s statewide races are less dominated by its metro areas, putting more emphasis on rural places, Kondik said.

“You’ve seen a lot of the white rural areas in both Minnesota and Wisconsin shift strongly to the right in recent years,” Kondik said. “But Democrats might have a little bit of a higher floor in Minnesota because of the higher four-year college attainment,” particularly in the vote-heavy Twin Cities and their suburbs.

Among the areas that have shifted to the right are western Wisconsin, an area that covers a large swath of the state but produces relatively few votes in statewide contests: In 2020, 15 counties north of Pepin County and west of Eau Claire and Ashland counties made up just 10% of the state’s votes for president.

Voters in these counties, including the few that favored Biden in 2020, have seen Republican margins increase since 2008.

That includes fast-growing St. Croix County, one of the area’s most populous counties and just across the border from the Twin Cities. In 2008, 51% of its voters favored John McCain. In 2020, 57% chose Trump.

Hambleton, the county’s Democratic party chair, called St. Croix County pink — with rural areas pink to red.

“I mean there are blue dots ... here in Hudson, New Richmond and River Falls,” he said.

Hambleton said Democratic voters tell him they are concerned with what they see as extreme GOP positions. Though the region has moved Republican in the long-run, Biden did improve slightly on Democrat Hillary Clinton’s margin in St. Croix County and similar counties in 2020, contributing to his win.

Rust said voters here have an independent streak. “For whatever the reasons are, people speculate, but I think the more rural an area, the more independent and self-sufficient people tend to be by necessity,” he said. “They value their independence and autonomy a little bit more.”

On Tuesday’s ballot, two state Constitution questions center on Wisconsin elections, which some political observers say could portend political leanings in November.

The measures are generally supported by Republicans and opposed by Democrats. It’s not clear that the questions will generate huge turnout, but their outcomes could be indicative of critical Wisconsin voters’ leanings heading toward November, said John Heppen, a professor in the University of Wisconsin-River Falls’ Politics, Geography and International Studies Department.

“It could be a sign of who’s more motivated to come out and who’s better organized, who’s better at getting out the vote,” he said.

The first question, if passed, would ban private grants from being used to administer elections. The debate stems from grants given to Wisconsin municipalities in 2020 by an election access nonprofit that received money from Facebook founder Mark Zuckerberg and his wife, Priscilla Chan. The couple have said the grants were intended to help people vote. Biden won many of the Wisconsin cities that received larger grants.

The second question, if adopted, would specify who can work the polls. According to media reports, the measure would add language already in state statute to the state Constitution.

While the ballot questions’ fates may hint at where Wisconsin is leaning this year, those outcomes won’t change the bombardment of ads, mailers, pollsters and phone calls to state voters that will start in the coming months as Democrats and Republicans alike look to tip the swing state electorate in their favor.

“The whole state is going to get attention because both sides should be scratching and clawing for every vote possible,” Kondik said.