With New Hampshire's primaries slated for Tuesday, President Joe Biden is not on the ballot because of changes in the Democratic National Committee calendar and former President Trump seems to have a lead on the Republican side. But more than one in five New Hampshire voters have never voted in the state before, including young people registering to vote for the first time, new residents and students. What does that mean for the election? Lisa Kashinsky of Politico and UMass Boston Political Science Professor Erin O'Brien joined Jeremy Siegel to discuss.

Here are four things to know before Tuesday’s primary.

Campaign season has been less busy than usual

The higher-profile candidates have not spent as much time shaking hands and answering questions as candidates of previous cycles, Kashinsky said. She described the mood as “muted.”

“Several of the candidates, of the remaining candidates, aren't even in the state today,” Kashinsky said. “Ron DeSantis has left. Trump is not here. Nikki Haley has had a relatively light campaign schedule so far that is picking up a little bit today. And then you have the two longshot Democrats [Marianne Williamson and Dean Phillips] who are campaigning here while Joe Biden isn't.”

Still, voters are excited to head to the polls.

“In New Hampshire, of course, this is effectively a birthright to get to vet and pick the next presidential nominees,” she said. “So voters are turning out, hundreds of people showing up to town halls and events and meet and greets for all the different candidates. Plenty of still-undecided voters, definitely leaning one way, but still open to being swayed even in this late stage.”

Polls on the Republican race are leaning toward Trump

In a Suffolk University/Boston Globe poll, 50% of voters surveyed said they would vote for the former president, with 36% supporting Haley and about 5% supporting DeSantis.

“DeSantis put all his chips in Iowa and isn't a good match to the electorate,” O’Brien said. “So I actually think it is, in New Hampshire, a two-person race.”

But polling doesn’t always align with what candidates end up doing, O’Brien said.

“Rationality and politicians, you know, don't always go hand-in-hand,” she said. “I think with Ron DeSantis, he's done. Whether he knows it or not, is a different thing. And New Hampshire is going to send that message.”

Haley, the former South Carolina governor, may be in a different position, O’Brien said. After New Hampshire, she heads back to her home state for the next primary vote on February 24. And some New Hampshire voters may be more likely to choose her, especially with candidates like former New Jersey Governor Chris Christie dropping out.

“The theory of her campaign is that they win in New Hampshire, or do very, very close to Donald Trump, and then go to her home state,” O’Brien said. “Nikki Haley's right when she says she's a better general election candidate, she has less baggage from the perspective of trying to win over those voters, the mushy middle, if you will, that determine elections in swing states.”

New voters and independents will have major sway

According to research by the Carsey School of Public Policy at the University of New Hampshire, 22% of New Hampshire voters have never voted in that state before.

“That's where New Hampshire is very interesting,” O’Brien said. “It's an open primary, so independents can vote. And there's a lot of in-migration to New Hampshire along the Massachusetts border.”

When the general election rolls around, both major parties’ candidates will likely be depending on independents and swing voters to turn out for them.

“Of course, New Hampshire is a very white electorate and unrepresentative in that facet,” O’Brien said. “But the fact that swing voters, individuals who have voted for Democrats and Republicans, individuals who maybe sometimes stay home, that they can have influence on the New Hampshire electorate.”

New Hampshire Democrats are pushing for a write-in Biden campaign

Biden is not on the New Hampshire ballot because of a spat between the Democratic National Committee — which moved their first primary to South Carolina — and New Hampshire, where state officials say they have a right enshrined in the state’s constitution to hold the first primary in the nation.

“New Hampshire takes very seriously their role,” O’Brien said. “It's sort of a dream from a political scientist perspective, that so many citizens are really engaged or going to town halls when it's freezing.”

But Biden hasn’t campaigned in the state, and whether that has an impact remains to be seen. New Hampshire voters, O’Brien said, “like to be courted.”

Other candidates, including Marianne Williamson and Rep. Dean Phillips, are campaigning in the state. Democrats are urging New Hampshire voters to write in Biden’s name on their ballots.

“Everyone on all sides in the Democrats, the write-in Biden folks as well as Dean Phillips, have been downgrading expectations,” Kashinsky said. “Every time you talk to them, it's a little bit lower of where they think it will be. They obviously just need to get the largest share of votes to claim some sort of victory, the write-in folks do. But it's really hard to tell right now.”