AUDIE CORNISH, HOST:
With less than a week to go before the first votes are cast in the presidential race, it's newspaper endorsement time. But do those endorsements affect voters? Harry Enten has been looking into this question. He's a senior political writer for FiveThirtyEight. Harry, thanks for coming on the show.
HARRY ENTEN: Thanks for having me.
CORNISH: So you focused on a key paper in a key state, the Des Moines Register. The paper backed Marco Rubio on the Republican side and Hillary Clinton for the Democratic nomination. So just to give us some context, how do you measure influence, right? What data did you look at?
ENTEN: So we essentially looked back at all the caucuses since 1988 on the Democratic and Republican side, and we looked at where these candidates were in the polls before that endorsement and where did they end up scoring on election night. Now that's not perfect, there are obviously other things that are going into it, but through that method we can generally see - did these candidates do better after the endorsements than we expected them to do before them?
CORNISH: What did you find?
ENTEN: We found that generally, in fact, the candidates who were endorsed did do slightly better in the final vote counts than they were doing in the polls before the endorsements. But it wasn't an overwhelming effect, at least for the Des Moines Register poll. They only did about three percentage points better versus where their polls were before the paper endorsed them. And in fact, two candidates, Bob Dole in 1996 and George W. Bush in 2000, went backwards and did worse on election night than they did in the polls before the Register endorsed them.
CORNISH: So is the idea that this matters basically when it's close? Does it help undecided voters or does it just, you know, boost momentum?
ENTEN: I think it really boosts momentum, you know? Remember, most people are not reading newspapers anymore. The Des Moines Register's circulation is down. But it helps give these candidates good press. And certain candidates who might be rising in the polls or are just aching to sort of break out, like John Edwards in 2004, were able take this endorsement and then were able to do considerably better on caucus night than they were doing in the pre-election polls.
CORNISH: Here's the thing. How do you know if it was the newspaper endorsement that made a difference or something else? I mean, every statistics professor who is listening to this is say, you know, correlation is not causation.
ENTEN: Sure. And I think that's something to keep in mind, is correlation is not causation. But we do know from the accounts at the time that Edwards received a lot of good media following this endorsement, so it leads us to believe that in fact, the endorsement may not have been totally responsible - in fact, it almost certainly wasn't for Edwards's rise, but it was something that aided in it. And I think any candidate who's looking to be aided in what are two very tight contests at this point on both the Democratic and Republican side would welcome an endorsement that would be able to help them do at least a little bit better in the caucuses.
CORNISH: You write about politics for a website, so I realize this question will have some bias, but is there something very throwback about this? I mean, how should we think about newspaper endorsements generally in this day and age?
ENTEN: You know, I tend to think newspaper endorsements don't really matter that much, especially in general elections when you're just not going to get a big surprise. You know, if The New York Times endorses Hillary Clinton, no one's going to say oh wow - you know, now I'm going to vote Hillary Clinton because most of the people who are reading that editorial would vote for her in a general election anyway. But if, say, The Times were to endorse Donald Trump, that would be big news. So, you know, I think endorsements can matter, especially when they're surprising. And they matter for candidates who are looking for at least a little bit of good press that can sort of start a momentum train. That's what they really do. They're not the be-all-end-all, but they help add to the good press that these candidates can get, and I think any candidate would welcome that.
CORNISH: Harry Enten is senior political writer and analyst for the site FiveThirtyEight. Harry, thank you.
ENTEN: Thank you.