Indiana may have the closest Senate race in the nation because Hoosiers are having a tough time choosing between their incumbent Democratic Sen. Joe Donnelly (pictured above right) and his Republican challenger, businessman Mike Braun (pictured above left).

It’s almost as if voters agreed to split right down the middle, with half of them for Donnelly and half for Braun. This means anything can happen next Tuesday, when voters have to make a final decision and cast a ballot for one man or the other. Or for the woman, Libertarian Party candidate Lucy Brenton.

Donnelly is seeking a second six-year term after first winning it in 2012. Braun comes in touting his business experience and time as a member of the Indiana House of Representatives.

Donnelly and Braun have been within a point or two of each other almost from the first day of the campaign, with a result that ScottRasmussen.com has pegged the race a toss-up for months.

And just last week, the Mike Downs Center for Indiana Politics at Purdue University Fort Wayne said Braun has 40 percent and Donnelly has 41 percent.

“There have actually been a couple of polls that have come out in the last week or so that show Braun ahead,” Purdue professor Andrew Downs, who co-authored the poll, told LifeZette. “So this is tighter than people thought. Donnelly has been looking good in a number of those polls, but the last couple have favored Braun.”

Brenton, with 8 percent, could be the deciding factor in the race because most of her support would likely go to Braun if she were not in the race.

Related: Mike Braun Has Plan to Shake Up Joe Donnelly, Political Class

“No matter what source you look at, it’s a close race,” Downs said. “Unlike a lot of other races where campaigns are just worried about turning out their base, I think they will be working very hard through Election Day to motivate undecided voters to come their way. But I also think there will be a push to try and convince some red voters to defect.”

Brenton’s 8 percent could be crucial to Donnelly’s chances, and the Indiana Democratic Party even circulated a mailer suggesting she is the real fiscal conservative.

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CBS News found in a poll Sunday that Braun earned himself a slight lead with a 46 to 43 percent advantage. Downs cautions, however, that voters in the state tend to favor incumbents since they know them and their character. Donnelly is also seen as fairly moderate, which is less of an issue among conservatives in the state.

“It is truly a close race and I think that both sides have a very good idea of who the undecided voters are and what messages that will resonate with them,” Downs said. “We’ve already been seeing that in the way they have been campaigning recently.”

Related: Donnelly Warns of Republican Surge in Wake of Kavanaugh

Donnelly comes into the race claiming numerous accomplishments with his work on education, veterans, the economy, and health care. He previously served three terms in the U.S. House of Representatives.

“Donnelly has been talking about not being an extremist,” Downs said. “He has run at least two television commercials that are critical of the far Left and far Right, which I think is clearly an attempt to appeal to moderates and undecided voters. And we’ve also seen with Braun an emphasis on economic development and health care, which are the top two issues in the state.”

Braun is founder and president of Meyer Distributing and owner of Meyer Logistics, which deal with marketing and distribution of automotive specialty products. The U.S. Chamber of Commerce endorsed him, and he has served in the Indiana House of Representatives since 2014.

Braun has argued that there isn’t enough accountability in the federal government and positioned himself as an outsider who will disrupt the stagnant, self-serving Washington political class. Trump has actively campaigned in Indiana for Braun.

Related: Trump Tells Hoosiers He Needs Republican Mike Braun in the Senate

“I think where the president is really useful is in Missouri and Indiana,” Republican pollster Adrian Gray told LifeZette. “I think he’s had in the final weeks three or four stops in each state. Those are the two places where I think he can really move the needle just by him being the head of the party, his brand and everything.”

Trump won the state by 19 points in 2016 and plans to hold a rally for Braun Friday alongside Vice President Mike Pence.

Donnelly was leading in fundraising shortly after the primary elections, but that has since largely leveled off. He has spent a total of $13,803,547 out of the $16,031,094 his campaign has raised, according to the most recent government data October 17. Most of those funds came from large individual contributions at 54 percent.

Braun has mainly self-financed his primary campaign and has since spent $14,760,273 out of the $16,148,137 his campaign has raised in the general election.

Justice Brett Kavanaugh’s brutal confirmation battle is a big factor in Braun’s support. Rasmussen Reports found in a survey that 62 percent of Republicans are more likely to vote because of Kavanaugh, compared to 54 percent of Democrats.

Donnelly was considered a potential swing vote since the president won the state by so much, and he voted to confirm Justice Neil Gorsuch in 2017. But he ended up voting against his nomination.