AUDIE CORNISH, HOST:
It's election day in Wisconsin where history suggests Donald Trump and Hillary Clinton should win the Republican and Democratic presidential contests. Wisconsin primary voters have gone with their parties' leading candidates at every opportunity since 1988, but tonight could be different. The underdogs Ted Cruz and Bernie Sanders could win in a state that's been the frontrunners' friend. Joining us now to talk about Wisconsin is NPR senior editor and correspondent Ron Elving, who actually started his reporting career, right?
RON ELVING, BYLINE: Yes.
CORNISH: So tell us. Why does Wisconsin typically go with the leading candidate?
ELVING: It's a state that usually tracks pretty closely with national voting trends. And you know, it helps to be in the middle of the calendar so you see where things are going in the previous primaries. You know, if you set aside - this is how strong this is. If you set aside the Democratic primary in 1984 and a couple of favorite-son votes in 1964, Wisconsin has voted for the leader and eventual nominee in both parties all the way back to 1956. But this year, we're not seeing the same bandwagon effect we've seen in the past.
CORNISH: But give us more context. What's different this year?
ELVING: The leading candidates, Trump and Clinton, are not an ideal fit for Wisconsin. Trump has never reached his national polling level here, and he's notably unpopular in the three suburban counties outside Milwaukee. And they are the key to any Republican primary in the state.
On the Democratic side, Clinton lost here badly in 2008, and this time around, she's replaying the scenario from that 1984 anomaly. That was the other time that Wisconsin Democrats rejected the leading contender and eventual nominee. Walter Mondale, who had been vice president previously - he lost a close one that year to Colorado Senator Gary Hart.
CORNISH: Whose supporters you say were a bit like Bernie Sanders are today.
ELVING: Yes. I mean, Hart was that year's insurgent phenomenon. He won New Hampshire. He had the outsider image, the antiestablishment appeal. And he did especially well with young people, especially well with independents and not so well with minorities.
CORNISH: Now I want to turn to Republicans. Donald Trump won primaries in Michigan and Illinois, but he's fallen behind in most of the polling, at least, in Wisconsin. What's going on there?
ELVING: Ted Cruz has risen while Trump has seemed pretty much stuck around the low 30s. And you know, there might have been some cumulative effect from some of the controversies around Donald Trump, but more basically, he had never really closed the deal in this state either with the establishment or with the activists in the state. And his decision to double down on his criticism of Governor Scott Walker seems hard to understand given, well, Scott Walker is overwhelmingly popular among Wisconsin Republicans - something like 80 percent approval.
CORNISH: Right - and has, obviously, a huge network in the state - right? - (laughter) in terms of his ability to turn out votes.
ELVING: Like no one else.
CORNISH: Now, if Trump stumbles today, who benefits the most?
ELVING: Cruz appears to be the likeliest to actually win in the state. John Kasich possibly has a shot at a few delegates. You can get three delegates by winning just one congressional district. He could win one or two.
But the real winner would be the Stop Trump movement. We already know that Donald Trump cannot get to the delegate number he needs to be nominated on the first ballot before the final week of the primaries California, New Jersey and so on. A bad loss in Wisconsin would make it much more difficult for him to do it at all before we get to the convention itself, so that raises the odds of an open convention in Cleveland in July.
CORNISH: That's NPR senior editor and correspondent Ron Elving. Ron, thanks for coming to the studio.
ELVING: Thank you, Audie. Transcript provided by NPR, Copyright NPR.