The race for the First Congressional District Democratic nomination between incumbent Rep. Richard Neal and challenger Holyoke Mayor Alex Morse is heating up. WGBH New Host Henry Santoro spoke with WGBH News Political Reporter Adam Reilly to go over Monday night's debate. The transcript below has been edited for clarity.

Henry Santoro: Can you lay out why Mayor Morse has turned into such a contender to Neal, who chairs the Ways and Means Committee? He's such a prominent political figure in Washington.

Adam Reilly: He is. And he not only chairs the Ways and Means Committee, but he's been in Congress for about three decades. So he's the definition of an entrenched incumbent. Morse, as some of our listeners will know, has been mayor of Holyoke since he was 22 years old. That alone made him a public figure of note, at least in the world of Massachusetts politics. He was elected mayor when he was 22, right out of college. He's now 31 years old. Over the years, he has become known as a reliably progressive voice in the Western part of the state. He's always been seen, ever since he became mayor, as a person on the rise, a person to watch. And more recently, he's been in the news a lot talking about mismanagement, as he sees it, at the Holyoke Soldiers Home, where there was that terrible [COVID-19] outbreak earlier this year.

So for a constellation of reasons, he's a prominent figure. And Neal is someone who — even though he's entrenched, even though he's been reelected again and again — is in a way, paying a price for this moment that we're at, where being an entrenched incumbent can be a liability rather than an asset. Think of Ed Markey [and] think of Mike Capuano, before he was ousted by Ayanna Pressley a couple of years ago.

Santoro: When this race was announced between these two candidates, did you think for a second that Neal would have anything to worry about?

Reilly: Well, I thought it was a possibility. I remember going out and covering for WGBH the last time Neal was running for reelection, his challenge from a woman named Tahirah Amatul-Wadud, and she was much more of a political neophyte than Alex Morse, and she still got a big chunk of the vote. Not enough to keep Neal up on election night, I don't think, but there was substantial support — sort of like when Tom Menino was mayor of Boston and people ran against him. There was always a big chunk of the population, not enough to win elections, but a reliable portion of voters that didn't want to see him reelected. So I'm not surprised that this race has become as close as it has.

Santoro: You alluded to this just a couple of minutes ago. The big story lately in this race has been allegations of impropriety aimed at Morse by the College Democrats of Massachusetts. Can you recap those claims and the counterclaims that have followed?

Reilly: Yeah, I'll try to give a broad brush version. Earlier this month, the College Democrats of Massachusetts sent Alex Morse a letter basically telling him to stay away. That letter was obtained by the UMass Amherst Daily Collegian. Morse, in addition to being mayor of Holyoke, has been a lecturer at UMass Amherst. In the letter, the College Democrats accused Morse of behaving inappropriately with students online on dating apps like Tinder, Grindr and also on Instagram. They said that in some cases he was having sexual relationships with students.

Morse responded to this by putting out a statement in which he said that any relationships he has had have been consensual, that he's never abused his position of power — either as mayor of Holyoke or as a lecturer at UMass Amherst — and he also suggested, and these are points he's made subsequently in interviews that he's given, that the allegations were inherently homophobic, saying there's a long tradition of people who are gay having their private sex lives scrutinized in a way that straight people don't have theirs scrutinized. And he argued that that was what was at play here, or at least part of what was at play.

Then, the website The Intercept has been all over this story since the allegations first came out, and they have reported on evidence of a coordinated, premeditated campaign to use these allegations to derail Morse's candidacy. And there are individuals connected to the state Democratic Party, the Massachusetts Democratic Party, who seem to be linked to these premeditated efforts. So there's been twist and counter twist, and it's hard to say right now who this is helping and who it's hurting.

Santoro: How did this play out on the debate stage last night?

Reilly: It was the first question and, to my ear, elicited the sharpest exchanges. Morse said, as he said before, I'm not going to apologize for being a young gay man who has sex with other adults. He said it is now clear there was, in fact, an organized campaign to use this stuff to take me out politically. And he reiterated his suggestion, without offering hard evidence, that Neal was in some way involved with that campaign. Neal says he was not involved. As he put it last night, he doesn't even know the names of the students who've come forward. He went on to say, however, those students should be heard. And then to add a caveat, saying on a couple occasions, there is no room for homophobia in my campaign.

Santoro: How does something like this end? How does Morse wrap this up and just put it aside?

Reilly: Well, I don't think he does put it aside. I think what he's hoping is that this is going to go down to his benefit. He has reported that he's had his biggest fundraising day in the entire campaign after the allegations came out. I think he is hoping that people see him as the victim of an unjust smear campaign and are more likely to vote for him now than they were previously. But I should note, before we wrap up, this is the most interesting and the most incendiary part of this contest, but it's not the only thing at stake here.

Morse is making an argument against Neal, which is similar to one that we've heard other challengers make against longtime incumbents. He basically says Neal is too used to doing politics as usual; that even though he is Ways and Means Chair, he hasn't used that position to help the district enough; [and] that he has become beholden to special interests who've given him a lot of money over the years. Neal counters in a way that we've heard other incumbents counter. He says essentially, Alex Morse has these big ideas about how politics should be practiced, but he doesn't really get the way Washington works. I do. I've been really good for the district, and that's why you should send me back.

So that's going to be another thing that people are weighing as they decide how to cast their vote. Do they want politics as usual? Or do they want a more ambitious, more progressive vision of politics that skews more to the left?