Manchester, New Hampshire (CNN) Bernie Sanders isn't only competing for supporters with Hillary Clinton in the heated final days of the New Hampshire presidential primary race. His campaign is also going after some voters weighing a candidate not even running for the Democratic nomination: Donald Trump.

Because independents can register as "undeclared" in New Hampshire and then vote in either party's primary, the Vermont senator's campaign has noted some of these voters are wavering between Sanders and Trump.

Sanders' team has even prepared a script as part of their literature for volunteers who encounter voters who say both Trump and Sanders' "outsider" status appeals to them.

"A lot of people feel like this country isn't working for them -- because it's not," it reads. "The solution to that is not to turn to someone like Trump, with a message of hate, xenophobia and division -- it's to elect a leader with integrity like Bernie, who's proven time and again that he won't be held hostage by moneyed special interests."

The Trump campaign defended its candidate to CNN, however, with spokeswoman Hope Hicks saying that, "Mr. Trump is the only candidate running for President self-funding his campaign. He is not beholden to donors and special interests. His only special interest is the American people." She added, "Mr. Trump's message has resonated across the country."

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Sanders and Trump are the two candidates who enjoy the most support from independent voters, according to polls. And with 389,472 "undeclared" voters making up a little more than 40% of registered voters, according to the New Hampshire Secretary of State's office, that margin can make a difference.

Republican John Kasich, the Ohio governor, would actually enjoy the biggest boost from undeclared voters if they turn out in high number because it would improve his position the most.

According to a WBUR/MassINC poll, light independent turnout for the Republican primary would have Kasich tied for fourth place with former Florida Gov. Jeb Bush at 9%. Trump has the most support at 28%, and Florida Sen. Marco Rubio and Texas Sen. Ted Cruz tie for second at 12% each.

With heavy Independent turnout, Kasich's support grows to 12%, Trump drops one point to 27% and Cruz and Rubio's also drops one point to 11% each.

On the Democratic side, low Independent turnout means Clinton comes in at 39% to Sanders 54% and with high turnout, Sanders' lead expands to 18%.

"There's a big chunk of independents that do switch which ballot they pull between primaries," Steve Koczel, president of the MassINC Polling Group, told CNN. "There are certain candidates who would like to see as many independents as possible crowded into their primary."

Right now, 46% of undeclared voters have decided to participate in the Republican primary compared to 40% in the Democratic, according to a WBUR/MassINC poll. Of voters who are undecided about which party to vote for, slightly more are learning towards picking a Democratic ballot -- 24% to 19%.

The WBUR/MassINC poll also found that, of undeclared voters, Democratic candidates have much higher favorability ratings than Republican candidates -- but that antipathy can actually push some undeclared voters to choose a Republican ballot.

"We have two folks on the Democratic side that have some interesting promise. We don't have that on the Republican side," David Luchsinger of Madbury told CNN at an event for New Jersey Gov. Chris Christie in Hampton.

"I want to vote in the Republican primary to try and push forward the best candidates," he told CNN, adding that he voted for Barack Obama in both past presidential elections. "The people being touted as the leaders right now on the Republican side scare me."

Luchsinger decided to vote for Christie following his debate performance Saturday night and the town hall he had just sat through, but he was still unsure whom he would vote for in a general election. He also told CNN he found Kasich attractive for his focus on bipartisanship.

As Kasich fights to break away from a cluster of candidates under Trump, he has openly courted independent voters, embracing an endorsement from two different newspapers with liberal readerships: The New York Times and The Boston Globe.

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"I'm an independent guy. The Republican Party is my vehicle, but it has never been my master," Kasich told a town hall audience recently in Keene.

Kasich often mentions the large amount of Democrats who tell him they are interested in him. "I ought to be running in the Democrat primary," he said Saturday in Manchester.

But Kasich chief strategist John Weaver told CNN, "He was just joking around," saying the campaign doesn't change messages to target different groups of voters but instead is focused on a message of inclusion.

"We're reaching out to unaffiliated voters, disaffected Democrats, but primarily Republicans, and that's who we're going after and we're seeing our numbers rise with both unaffiliated and Republicans," Weaver said.

Trump's team in New Hampshire has also acknowledged the crossover with some Democratic-leaning voters, blasting out an email to supporters in October reminding them to change their registration to undeclared or Republican in order to vote for Trump in the primary.

Sanders' campaign has gone even further with its talking points for volunteers.

"We are trying to make a connection with those folks and we are trying to do it from the perspective of seeing solutions through tolerance and equality and not through hate," Sanders' state director Julia Barnes told CNN.

It's a message the candidate himself echoes at his events.

"The only way we transform America is -- how? How do we do it?," Sanders called out to the audience at the rally. "Together!" they called back.

"Together, that's exactly right," he said to cheers. "When people come together and demand we have a government that represents all of us and not just a handful of wealthy campaign donors, when we do that there is nothing that we cannot accomplish."

It's a positive appeal that Michael Crossman, an 18-year-old undeclared voter from Newton, finds more compelling than what's coming from the Republican side.

At Sanders' Rindge event, Crossman told CNN that he usually identifies as a Republican but that the Vermont senator had changed that.

"I probably want to be a Democrat now because of Bernie Sanders," Crossman told CNN, saying no one else is focusing on income inequality the way Sanders is.

"I can't vote for a man like Donald Trump because he's just a terrible man," Crossman told CNN. "If I had to choose I'd probably be Republican, but I can't be Republican in this election. It's immoral."

Another attendee at the Sanders event stressed that party affiliation doesn't matter.

"I'm here because this is all about America," declared Chris Peahl. "It doesn't matter right or left, it's what we have here for America."