Craig Gilbert

Milwaukee Journal Sentinel

Bernie Sanders will be on friendly turf when he visits Wisconsin Friday.

He won the Democratic primary here three years ago, beating Hillary Clinton in 71 of 72 counties. And Sanders got the best marks of any Democratic candidate in a Wisconsin poll of Democratic and independent voters released Wednesday.

This state’s 2020 presidential primary is so far away and comes so late in the nominating fight that handicapping the Democratic race in Wisconsin is a pretty pointless exercise.

But here are a few things to keep in mind about Wisconsin’s role in the fight for the Democratic nomination, based on the political calendar and the latest polling:

A long, protracted Democratic fight

Wisconsin’s late primary date next year means the action could be effectively over before it gets here. Based on the unofficial calendar, about 30 states will vote before Wisconsin: the four early states of Iowa, New Hampshire, Nevada and South Carolina in February 2020; and a multitude of states in March, including about a dozen on Super Tuesday — March 3.

But if the race rumbles on — which could easily happen in a huge open field like this one — then Wisconsin’s primary will be standing alone on April 7, commanding center stage. Right now, there are no other primaries scheduled in the three weeks preceding Wisconsin (just a few small-state caucuses) and none in the three weeks after.

A similar circumstance four years ago created a dramatic Wisconsin showdown late in the GOP race, with Ted Cruz dealing Donald Trump his final big setback before Trump wrapped up the nomination.

Like the Republicans last time, Democrats have a massive field of candidates, with no overwhelming favorite, in volatile times. The field will certainly be heavily winnowed by early April. But there is a very plausible scenario for a titanic Badger State clash if there are still two or three contenders left after the gauntlet of February and March.

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Some early clues about Wisconsin

Sanders and Joe Biden got the best ratings in a statewide poll released Wednesday by the Marquette Law School. This was not a “horse race” survey of potential Democratic primary voters (which wouldn’t be worth much since the field will be much smaller by the time it gets to Wisconsin). Instead, Marquette pollster Charles Franklin asked a subset of voters (Democrats, independents who lean Democratic and independents who don’t lean toward either party) to evaluate 12 Democratic candidates. For each one, voters had the option of rating them “a top choice,” “an acceptable choice,” someone they “would not support,” or someone they haven’t heard enough about to have an opinion.

This is the percentage of voters who rated each candidate a top choice, and in parentheses, the share who rated them either a top choice or acceptable choice (voters could rate more than one candidate "a top choice"). Only the top nine candidates in the poll are listed here:

Vermont Sen. Bernie Sanders: 32 percent “top choice” (70 percent “top choice” or “acceptable choice”)

Former vice president Joe Biden: 29 percent (72 percent)

Sen. Elizabeth Warren: 17 percent (52 percent)

Sen. Kamala Harris: 11 percent (38 percent)

Former U.S. Rep. Beto O’Rourke: 10 percent (37 percent)

Sen. Cory Booker: 9 percent (38 percent)

Sen. Amy Klobuchar: 8 percent (35 percent)

South Bend (Ind.) Mayor Pete Buttigieg: 7 percent (25 percent)

Former cabinet secretary Julian Castro: 4 percent (22 percent).

Sanders and Biden get the highest ratings, though that is heavily influenced by the fact that they are the best-known figures in the field. In fact, the ranking above is very close to the ranking you’d get if you simply put the candidates in order of how well known they are.

But there are some interesting nuggets in the poll. Sanders’ ratings improved since Marquette’s January poll (from 23 percent rating him a top choice to 32 percent) while Biden’s went down slightly (from 32 percent rating him a top choice to 29 percent). This was a period when complaints appeared in the media from women whose encounters with Biden made them feel uneasy. Ratings for most of the other Democrats improved slightly from January to April as they became better known.

Combining the January and April polls to get a bigger sample size, Sanders gets the highest ratings among liberals (36 percent rate him a top choice) but he’s followed closely by Biden (34 percent), then Warren (23), Harris (16), O’ Rourke (15), Booker (14), Buttigieg (13), Klobuchar (9) and Castro (5). Sanders dominated the liberal vote in the 2016 Wisconsin primary, and Friday afternoon he will hold a rally in the most liberal part of the state, Madison.

But among moderates and conservatives, Biden gets the best marks (29 percent rate him a top choice), followed by Sanders (22), Warren (11), O’ Rourke (8); no one else is above 5 percent. While 22 percent of this group rate Sanders "a top choice," another 29 percent said he was someone they "would not support," a high figure for this poll. The candidates aren’t as well known among moderate Democrats and independents, and the contest among more centrist Democratic voters looks even more wide-open at this point than it is among liberals.

Biden gets higher marks than Sanders among college-educated voters, women and voters 60 and over. Sanders gets slightly higher marks than Biden among men, and far higher marks among voters under 30. Sanders and Biden get similar ratings, averaging the two polls, among blue collar voters (those without a college degree).

Wisconsin’s history in Democratic primaries

Past Democratic primary winners in Wisconsin are Sanders over Hillary Clinton in 2016 (56 percent to 43 percent); Barack Obama over Hillary Clinton in 2008; John Kerry narrowly over John Edwards in 2004; and Bill Clinton narrowly over Jerry Brown in 1992. There is clearly a large constituency in a Democratic primary in Wisconsin for a progressive populist such as Sanders, as shown by his double-digit win three years ago. But the state’s high-turnout open primary (since there is no party registration in Wisconsin, anyone can vote in either party’s contest) also means a lot of independents and moderates will be participating, which can have unpredictable effects.

“I think Wisconsin will still be relevant when it comes to the April primary,” said Jason Rae, the Wisconsinite who serves as secretary to the Democratic National Committee. “It’s really about the delegate math.”

Democrats award their convention delegates on a proportional, not winner-take-all, basis, making it harder for one candidate to lock in a majority.

Factor in a large field that could fragment the vote in most states, and you have a recipe in 2020 for a big Wisconsin showdown in the home-stretch of the nominating fight.