It's been a busy 24 hours in politics as Sen. Ed Markey and Rep. Joe Kennedy took the debate stage ahead of the state's primary, and Joe Biden announced Sen. Kamala Harris as his running mate. WGBH Morning Edition Host Joe Mathieu spoke with WGBH News Political Reporter Adam Reilly about his observations on the Senate debate, as well as his thoughts on what a Biden-Harris White House could mean for another well-known former Democratic candidate: Sen. Elizabeth Warren. The transcript below has been edited for clarity.

Joe Mathieu: Start locally with the debate. You've been watching these two guys and following this campaign along with the rest of us, even with all the distractions that the coronavirus has brought. Everybody wakes up and realizes the primary is in three weeks and things got pretty intense last night — some personal, passionate exchanges. Did it change anything?

Adam Reilly: I will say that to my spectator's eye, I thought this was a strong debate for Joe Kennedy because he was kind of controlling the terms of what they talked about and when they talked about it, forcing Markey to play defense in a way I don't think I'd seen him do in the previous debates. Neither one of these guys, I would say, is a naturally skilled debater. It's not a great format for either of them.

So in the last debate, after your opponent, the incumbent, has made what was supposed to be an easy cruise for you into a more competitive race — I think it's great for Kennedy to take a bit more control, just practically speaking. It's hard for me to imagine anyone who wasn't all in on one of these guys watching what transpired last night and thinking, "I'm going to change my mind because I've seen something so attractive." I feel like at this point, most people are probably making up their mind. I felt like they were preaching to the choir to an extent [and] reinforcing their appeal, but overall, a good night for Kennedy. Long answer.

Mathieu: No, but it kind of takes a long answer because this has been a confusing race. It's essentially too close to call. They cannot really, at least in the traditional sense, retail politics. So these debates are kind of it; this is the way they get to people, Adam.

Reilly: Well, and one thing that I was thinking about last night, watching this on TV, as I think most people probably were if they were tuning in, is just the aesthetics of this. And in addition to what I said earlier about Kennedy taking control yesterday evening, I think that the split-screen format that you get on TV is unkind to Markey in a way that it is not to Joe Kennedy. I remember this from his primary run against Steve Lynch a few years back. He has a tendency to look sort of angry, but also a little bit guilty when the cameras are on him. I don't think that's because he is feeling angry and guilty, but it's just the way his face looks when he is challenged. And to see that again and again last night, if you're someone who's undecided, is probably not a bad thing for Kennedy. Now, we should talk about that remarkable exchange where Markey went after Kennedy for his family's alleged involvement in the super PAC that's trying to bolster his campaign, and then Kennedy came back with the accusation of online hate speech. That was quite a moment. And I felt for a little bit like Markey was gaining the upper hand in a way he hadn't. But then once you bring up Lee Harvey Oswald as Joe Kennedy did, that left me sitting there with the slack jaw.

Mathieu: This is what Adam is referring to.

Clip of Rep. Joe Kennedy: Your campaign supporters have bullied my supporters, have put out tweets saying that Lee Harvey got the wrong Kennedy. That where is Lee Harvey Oswald? And not a word coming from you. Not a word.

Mathieu: That was tough, Adam. Are you suggesting it was a bad choice to bring that up, or you were just surprised?

Reilly: No, I'm not suggesting it was a bad choice for Kennedy to bring it up. I think it was actually a very effective way to end a little momentum that Markey seemed to be developing when he kept saying, "Tell your father not to spend money on this super PAC." I think it's important to note, I saw someone provide an example of one of these Lee Harvey Oswald-referencing tweets when I asked for an example yesterday on Twitter. I don't know that the people who are sending [the tweets] are, in fact, Markey supporters, as opposed to just trolls who are getting off on the ability of social media to provide a venue for the most loathsome things you want to say in the privacy of your own home. I don't know how it really shakes down behind the scenes. But the long and short of it is Markey ended up having to strike a penitent note and saying I would never condone anything like that. So I think on the whole, that exchange redounded to Kennedy's benefit.

Mathieu: Indeed, Markey had his moment, as Adam Riley is reminding us.

Clip of Sen. Ed Markey: Tell your father right now that you don't want money to go into a super PAC that runs negative ads. Just tell your twin brother and tell your father.

Mathieu: Talk about personal, calling out family members and in this case, family members who he once served with, Adam. Joe Kennedy did remind us a few times Ed Markey's been in Congress for 47 years, which is longer than Joe Kennedy's been alive.

Reilly: He did remind us that. In a way, when you boil it down, that's kind of at the core of the argument Kennedy is making, right? He says that Markey is not doing the job of a senator the way you need to — that Markey sees it as just going to Washington, D.C. and voting the right way, passing the right legislation when, in fact, the times call for building a political movement. And yeah, if you note how long he's been in Congress, that drives home that idea that there's a lack of vigor on the part of Markey. It's not the way Kennedy puts it, but it's the argument he tries to make.

Now, one thing that I would note is there's a little bit of presentism at play there, by which I mean you get Markey being held to the standards of the day by Joe Kennedy when, in fact, a couple of decades ago the Democratic Party was in a very different place. Case in point, Markey's support for that 1994 crime law, which Kennedy hit him on pretty effectively last night. It's worth pointing out that Joe Biden, the Democratic nominee for president, backed that same law [and] has since apologized for it. I'm pretty sure that the late Sen. Ted Kennedy supported the law in question. It's where the Democratic mainstream was at the time, and I don't know that Markey is doing a good job explaining that [and] providing that information to younger voters who might be sympathetic to the criticisms Kennedy's offering.

Mathieu: We got so wrapped up in this race, we never talked about the other one. I was going to ask you about Elizabeth Warren because you wrote a great piece on what this means for the one-time front runner. Look, we have 30 seconds, Adam. Does this change her standing in the Senate? And might she play a role in a Biden White House, if there is one?

Reilly: The smart political observers I talked to, including Wilnelia Rivera, who I know you talked to earlier today, as a whole they made the case that Warren might be stronger on the outside than on the inside. If she's in the administration, she has to sublimate her own priorities to Biden's. If she's in the Senate, she doesn't have to do that. And Wilnelia pointed out she could be a huge asset on the campaign trail. People in Massachusetts don't always remember this, but she is a terrific retail campaigner. So her stature may be a little bit diminished, but she's still a really, really important figure.