On the road in Manchester, N.H. — before the first votes are cast in the first-in-the-nation primary on Tuesday — WGBH Morning Edition host Joe Mathieu spoke with Andy Smith, the director of the University of New Hampshire Survey Center, where he is also a professor of political science. This transcript has been edited for clarity.

Joe Mathieu: Andy, it's great to see you. We're finally here.

Andy Smith: We're almost around the corner, it's the home stretch.

Mathieu: It's like Christmas Eve for you, right? This is the this is the real stuff. And you guys have been running numbers continuously, as we discussed last week on Morning Edition. You've had kind of daily updates for the final stretch here. And I wonder if you're seeing similar numbers of Bernie Sanders' lead, a bit of a [Pete] Buttigieg surge as you were even a week ago, or if the landscape is changing.

Smith: I don't think it's changing too much. A little bit of variation. We're showing Sanders in the lead, as well. Pete Buttigieg had a really strong trajectory coming out of Iowa, but that seems to have leveled off. I look at Iowa as like a snow globe. You shake it up and things bounce around for a little while, then they kind of settle down.

The other thing that's happened is that Joe Biden has also kind of staunched the bleeding a bit. He's stabilized around 11 percent, but he's significantly below Sanders and Buttigieg, who are at the top. Sanders separated himself a little bit. But I think one of the key things is: half the voters still say they have not decided who they're going to vote for yet. And that's really the critical thing to remember about the New Hampshire primary, is that so many people here make up their mind at the end because there's no reason for them to make up their mind earlier.

Read more: PHOTOS: New Hampshire Gears Up For First-In-The-Nation Primary

Mathieu: That is true, though, right? People like to poke fun at New Hampshire, sometimes, like people are intentionally not paying attention just for the pride of being able to say they've not made up their mind yet or will change their mind. But when you're meeting candidates every day and when you're surrounded by ads to the extent people are in New Hampshire, that's a real thing, right?

Smith: Absolutely. And first off, most people up here don't meet a candidate. That's kind of a myth that we post around. Only about 10 to 15 percent of people in the state will actually meet a candidate.

Mathieu: So forget meeting them twice. It's actually not like the old story.

Smith: No, myths are pretty good. But think about this. New Hampshire has really high turnout. The secretary of state is anticipating turnout to be around 50 percent. The record turnout in Iowa is 16 percent. So that means here in New Hampshire, you just get regular voters who really aren't paying too much attention to this. They'll come out and vote, but they pretty much like all of the candidates, they're all Democrats to them. They're not going to know the issue position differences between these candidates. So they're going to pay attention to things that happened over the last couple of days and [let that] help make their decision. And it's really critical to remember that very few of these voters in New Hampshire are really wedded to one candidate, that they're really strong supporters. They're kind of like a moth, like choosing a flavor of ice cream. Which one's your favorite on any given day? Could be something else.

Mathieu: But you're showing Bernie Sanders in a commanding position, right? That seems to be consistent with all the polls, or should we anticipate maybe something changing?

Smith: Yeah, he's leading. He's outside of the margin of error, but it's not that far. I think 'commanding' might be putting it a little bit too much, because so many people make up their minds at the end.

Think about back to 2008. Barack Obama, in the average of all of the final polls, had about an 11-point lead over Hillary Clinton. She won by two and a half points. The problem that we have, is we finished up our interviewing Sunday night. In the exit polls, for example, in 2016, for Republicans, 47 percent of Republicans say that they said they made up their mind in the last three days. Twenty-five percent said they made up their mind on Election Day. We're asking people who they're going to vote for and they don't know who they're going to vote for. So that's why you have to be very cautious about predicting what's going to actually happen from polling that's done on the Sunday night before the Tuesday election.

Mathieu: So the so-called undecideds will decide who wins the New Hampshire primary at this point?

Smith: I think so. They certainly could. That said, I don't see anything that's really happened over the last several days that's caused this race to get shaken up much. Coming out of the debate, pre- and post-debate, the two candidates that did best in the debate by having numbers go up are Joe Biden, believe it or not, and Amy Klobuchar. They kind of seemed to have stabilized a bit. Elizabeth Warren lost some ground after the debate, but nobody really had a huge difference pre- and post-debate. I don't see that there's been any other event that's going to really shake things up.

I guess the only other big event that's going to happen is Donald Trump coming into town tonight. And that's going to be blowing out most of the campaign coverage tomorrow.

Mathieu: And we think we know he's going to win the Republican primary.

Smith: I think the question is whether or not Bill Weld gets into double digits.

Mathieu: I understand. Can I ask you about our former governor, Deval Patrick? He's widely known up here, I think we can say. He's spent an enormous amount of time up here, not widely known in his own backyard, is that not fair to say?

Smith: I don't think it's fair to say.

Mathieu: So he's introducing himself himself, still. How come he can't crack 1 percent, 2 percent?

Smith: Started too late. Not enough money.

Mathieu: It's as simple as that? He was telling people, as well, here at this canvassing party: 'Don't let the media write that story in advance. No votes have been cast.' But the fact of the matter is, Andy, that there is a timeline here that candidates need to pay attention to, right?

Smith: The reason the candidates come here early is they set up organizations to identify voters. They knock on doors, they make phone calls. They provide literature to voters. Months ago, the big campaigns started this stuff back in the summer. And they built those whole organizations so on Election Day, they know who's a supporter of theirs and they're going to make sure that they pull them out to the polls. Patrick has not had the time or the money to invest in that kind of grassroots campaign work. And that's really what makes people who — again, aren't that interested in one candidate or another, not wedded to one candidate or another — you have to drag them to the polls, almost.

Mathieu: I wonder what your thought is on tomorrow night. You're going to be with us and I look forward to our primary coverage with you on election night. Is it an early call, or are we going to be confused, waiting for counties out in the middle of nowhere to report?

Smith: I think it could be problematic, only because the towns where Bernie Sanders ought to do well among young people, the college towns like Durham, they're going to report their numbers late because they're going to have so many people who show up for the first time and register. All of those things are going to have to be verified. And their numbers in Durham, for example, typically come in at 11 p.m. or later. That said, we'll be able to understand how poorly or well some people are going to do. Joe Biden, if he doesn't do really well in Manchester, he's really got no chance in the rest of the state. In Manchester, numbers will come in between 7:15 p.m. and 7:30 p.m.