The Walz VP pick surprised much of the country. What went into Harris’ decision?

CATHY WURZER: The Harris-Walz campaign is just, as you heard, kicking off a series of rallies across key battleground states. And as we heard later, this afternoon, it's Eau Claire, Wisconsin, for Kamala Harris and Minnesota's Tim Walz. The decision to tap Walz was one that surprised many across the country.

So right now, we're going to take a bit of a deeper dive into that choice and how much it will actually affect Democratic chances at winning the election this November. We're going to talk with Chris Devine, a political science professor at the University of Dayton, Ohio, and the co-author of Do Running Mates Matter? Professor, welcome to the program.

CHRIS DEVINE: Cathy, thank you for having me. This must be an exciting day in Minnesota.

CATHY WURZER: Well, it was really exciting yesterday. It was pretty busy, too, I got to tell you.

[LAUGHTER]

CHRIS DEVINE: I believe it.

CATHY WURZER: And I'm wondering, you and other experts say the selection of a running mate, sometimes called the first presidential act, is important. What's your opinion of Harris's pick?

CHRIS DEVINE: It is important, and it's not because they deliver a home state. My co-author and I, Kyle Kopko, in our book, Do Running Mates Matter? and other research, we just found very little evidence of that, certainly not enough to count on it and choose, let's say, Josh Shapiro simply because of his home state. They don't tend to deliver blocks of voters. So Geraldine Ferraro and Sarah Palin, the first two women vice presidential candidates, we find no evidence that they increased vote share among women.

So where running mates matter, it's typically not in those ways that we talk about. It's more so in terms of how they influence the way we think about the presidential candidate. Knowing that Kamala Harris in this case, or Donald Trump when he chose JD Vance, could have picked basically anybody in the party. And of all those people, they picked this person to be their partner, not just on the campaign trail, but in the White House for four or eight years. That's very telling.

And I think for Kamala Harris, this is a good pick because the main thing that impresses voters, again, according to our research, lots of polling data through the years, and so on, the most important thing to voters is that the VP be credible, that this person could actually be vice president, even president of the United States. And so they need to have a good amount of experience and a range of experience.

I can tell you, looking at the VP finalists, I thought all along that Tim Walz was the strongest candidate because he was the only one who had not only executive experience as a two-term governor-- again, I'll compare him to Josh Shapiro, who is only in his first term-- but also he has federal government experience, including foreign policy experience, as a member of Congress.

CATHY WURZER: Hmm. So when you mentioned that a vice presidential pick says, for the voter, says something about the presidential candidate, is that why John McCain had some issues after picking Sarah Palin?

CHRIS DEVINE: That's exactly right. And much of our research is devoted to testing out the conventional wisdom. And sometimes things that feel true just actually aren't when you really dig into the data, the home state advantage being one of them. But there is this perception that Sarah Palin really hurt John McCain, cost him a bunch of votes. Actually, we do find that she cost him votes. It probably wasn't a lot. I mean, VPs matter on the margins.

But what we can show is that voters who thought that she was not ready to be president thought less of John McCain's judgment. Again, they're focusing on the presidential candidate. That's what really is the significance of the VP pick. And what her pick told voters about John McCain is that he didn't have the judgment, he didn't have the leadership skills necessary to be president, at least that's what some people took away. And he lost votes because of that.

If you flip it around, we were able to look at data from the same year in relation to Barack Obama, who, unlike McCain, had very little experience for a presidential candidate, was a first-term senator himself. Him selecting Joe Biden, who at that point had served for nearly 40 years in the Senate, actually made people think better of Barack Obama's judgment, recognizing his weakness and trying to bring someone by his side who knew Washington and foreign policy and so on very well. It made people think better of Obama's judgment and actually gained him votes.

CATHY WURZER: Now, according to the most recent poll that came out right before the pick was announced yesterday, more than 70% of those surveyed said they have no idea who Tim Walz is. So obviously, the Harris campaign is going to have to get pretty busy in telling the story of Tim Walz. I suppose they're going to have to tell it the way they want to tell it versus having them be defined by the other side.

CHRIS DEVINE: That's right. Tim Walz obviously well-known to your listeners in Minnesota. But around the country, of course, not very well-known. It's worth pointing out, that's actually not atypical for a vice presidential candidate after selection to not be very well-known. It's a little higher in this case than normal. But I'll give you an example.

In 2016, immediately after Mike Pence and Tim Kaine were selected, polling showed that actually in both cases, as it happened, 61% of the American public either had no opinion of these men or had never heard of them. JD Vance's case, by the way, most Americans did not know who he was, despite him being a high profile, bestselling author whose memoir, Hillbilly Elegy, was made into a movie.

So this is typical. And it makes the task of a campaign immediately after the VP announcement not just to say, OK, good, we're done, let's move on. They need to spend time introducing this candidate because people don't know who Tim Walz is, really. They don't know enough about JD Vance, although they've been finding out some. It hasn't been working out well for him. But it's the task of the campaign to define their candidate positively, and of course, for the opposition to define them negatively.

CATHY WURZER: What is the primary job of a vice presidential candidate during the campaign?

CHRIS DEVINE: Yeah, good question. Much like their service in the White House, they are there to support the president, or in this case, the presidential candidate. They're not there to go out on their own, leading in the way that they think is best. It's a subordinate role. That's part of the job application process. We're even hearing early reports that Tim Walz's willingness to apparently just support Kamala Harris in whatever way she needed helped him get the job. There's some rumblings, at least, that Josh Shapiro wanted to have a little more control over how he would conduct himself.

So whatever the message coming out of the campaign is, reinforce it. Campaign wants you to go here versus there? Go with it. The job is not to go rogue, to use a Sarah Palin reference here, but to follow the campaign's lead and just help it do the job that the presidential candidate and his or her staff has decided on.

CATHY WURZER: And given what we saw Governor Walz do last night in Philadelphia, you need to be able to forcefully attack your opponent.

CHRIS DEVINE: That's right. The traditional role people say a VP candidate is to be the attack dog. And this goes back to a time which feels like it's in the past now, where presidential candidates really didn't want to get into the mud. Of course, you needed to voice the criticisms of the other side. And a presidential candidate might do that a little more carefully. But generally, they wanted to stay above the fray. They want to act a little more dignified. And the vice presidential candidate could do the dirty work. Spiro-Agnew is a classic example of this in '68 and '72 for Richard Nixon.

Running against Donald Trump, he's his own attack dog. He's changed the rules on that. This is a role that he relishes. He would not want to cede it to a vice presidential candidate, JD Vance or Mike Pence in the past. And so Kamala Harris has had to be ready since she entered this race to go toe-to-toe with Donald Trump, to be her own attack dog. She didn't need her VP to do it for her. But it's good to have that reinforcement and maybe even a different style.

And I think what we're seeing from Tim Walz so far-- and again, for folks in Minnesota, you're well familiar with this, but the rest of us are just getting to know him a bit-- I think he's coming across so far as something of a happy warrior, someone who can make the attacks, but with a smile on his face and a laugh. And that might be the kind of thing, we'll see how it plays out, but it would tend to be the kind of thing that people receive better than someone who seems really angry and nasty about it. Perhaps he can make those same attacks and do it effectively, but also not drive up his negatives.

CATHY WURZER: I know there are some researchers who say that overall the choice of a running mate has a small, if any, effect on the final results. But I wonder, because this election appears so close, might running mates matter in the end?

CHRIS DEVINE: Sure. In a very close election, let's say it comes down to Pennsylvania, just one state. We saw this in 2000. Florida was decided by, I think it was 537 votes for George W. Bush. Anything could have decided that, honestly. Weather probably decided it in one part of the state versus another. So, yeah, it's possible in any election that any factor in the campaign could make the difference.

What Kamala Harris's team had to judge is whether they were so confident that it might come down to one state and someone could make the-- Josh Shapiro, obviously, in this case, or I guess even Mark Kelly in Arizona-- whether they thought that person could make the difference to base the entire choice on that one consideration. And that's where I think people have gotten over their skis with this Josh Shapiro thing.

He was a fine candidate in a lot of ways. He might be a presidential candidate in the future. But to rest everything on him being the governor of Pennsylvania rather than, say, if he was the governor of New Jersey, then it would have been a risk to take. I think the Harris campaign was wise not to base the entire decision on that one factor. Vice presidential candidates matter, but they matter at the margins.

CATHY WURZER: Say, Professor, final question, because you've done a lot of research on this topic. What are you going to be looking for here in the next 90 days or so?

CHRIS DEVINE: Yeah, I'm really interested to see how the campaigns go about introducing Tim Walz. And JD Vance, we're a little into it now. But there's still, again, room to define them. What's the driving message of both campaigns? Can they stick to that message? Can they be consistent about it? One thing we're seeing from the Trump campaign so far is a tendency to get distracted. They have an opportunity to paint Kamala Harris as a very liberal figure. And for that matter, choosing Tim Walz, a fellow progressive, they could go with that line of attack, focus on policy.

Instead, we're seeing some what I would call distractions with last week Trump's comments about Kamala Harris's racial identity and then doubling down on that. Today, apparently, we're hearing about claims of stolen valor against Tim Walz. I think they're getting distracted. They got to focus on policy. And if they can't do that, they're never going to drive home a message about why not to vote for Kamala Harris and Tim Walz.

CATHY WURZER: All right, Professor, really a pleasure. Thank you so much.

CHRIS DEVINE: Thank you so much, Cathy.

CATHY WURZER: We've been talking to Professor Chris Devine, co-author of the book, Do Running Mates Matter?