With Tammy Baldwin polling stronger than Joe Biden, could Wisconsin see a split outcome?

Two years ago, Wisconsin voted Democratic for governor and Republican for U.S. Senate.

It was the first time since the 1990s that the state had a “split outcome” for high office, with each party winning a major election (for governor, senator or president) on the same ballot.

Could it happen again in 2024?

In a new Wisconsin poll by Marquette Law School, the presidential race is a virtual tossup between Democratic President Joe Biden and Republican former president Donald Trump, while in the Senate race, Democratic incumbent Tammy Baldwin leads GOP challenger Eric Hovde by 5 points.

That means there’s is a 5-point gap in this poll between these two races, the kind of gap that makes a split outcome totally plausible in a state as competitive as Wisconsin.

Put another way, Baldwin is performing a “net” 5 points better in her Senate race than fellow Democrat Biden is at the top of the ticket.

That gap raises another question: How far ahead of Biden does Baldwin have to run to keep her seat in the event of a Trump presidential victory in Wisconsin?

This is not just a Baldwin question. Polls suggest that in several key states this year, the Democratic Senate candidate is running ahead of Biden, who has been dogged by low approval ratings and high negatives.

Let’s take a closer look in Wisconsin at the relationship between the Senate and presidential races, based on the latest Marquette poll of 871 registered voters, conducted June 12-20.

To make the comparison between these two races as clean as possible, I am using the same version of the “horse race” question with each contest. I’m using registered voters, not likely voters (since it’s too early to get a good measure of who is likely to vote).

I am including “leaners” in the results — voters who are undecided but express a preference when pushed to do so (that’s why there are virtually no undecided voters in the numbers cited below).   And I am using a version of the presidential horse race question that doesn’t include third-party candidates, in order to make an apples-to-apples comparison with the Senate contest.

In the Senate race, Baldwin leads Hovde 52% to 47%.

In the presidential race, Biden and Trump are tied at 50%.

In partisan terms, Baldwin is outperforming Biden in two ways. She is doing considerably better with independent voters than Biden is.  And she is getting more crossover support from the other party. Baldwin is winning 12% of Republicans and Republican “leaners” against Hovde, while Biden is winning 7% of the GOP vote against Trump.

The vast majority of voters are supporting the same party in both races in this survey, which is exactly what you would expect. But about 10% of voters are splitting their tickets between the two races, and Baldwin is benefiting a little bit more from this than Hovde.

In the new poll, Hovde is winning 8% of Biden voters, while Baldwin is winning 13% of Trump voters, according to Marquette pollster Charles Franklin.

Should we be surprised that Baldwin is out-performing Biden right now?

Not at all.  Her popularity ratings are much better than Biden’s.  In this survey, 45% of voters view Baldwin favorably and 44% view her unfavorably.  By contrast, 40% of voters view Biden favorably and 58% view him unfavorably.

Baldwin also has a strong election history, winning her Senate races by almost 6 points in 2012 and almost 11 in 2018.

In that 2018 race, her margin was roughly 10 points better than that of fellow Democrat Tony Evers, who won his race for governor that year against incumbent Republican Scott Walker by a single point.

In both her races, Baldwin has proven to be far more competitive in the state’s Republican-leaning rural areas than other major candidates in her party, helping her to “overperform” baseline Democratic numbers in much of Wisconsin’s west, north and center.

Her opponent, meanwhile, is still unknown to a lot of voters, and more disliked than liked by those who have an opinion. In the new survey, 23% of registered voters view Hovde favorably, 32% view him unfavorably and more than 40% don’t know him well enough to say.

For these and other reasons, it’s natural to expect the Senate race in Wisconsin to have a more Democratic tilt than the presidential race at this point.

But how large a difference between these two races is plausible come November?

Here is the modern history of Wisconsin elections that featured two major races on the same ballot (either a Senate and presidential race, or a Senate and gubernatorial race), with the winning margin for each contest and the gap between those margins:

2022: Democrats by 3.4 for governor and Republicans by 1 for Senate. Gap: 4.4 points

2018: Democrats by 1.1 for governor and 10.8 for Senate. Gap: 9.7 points.

2016: Republicans by 0.8 for president and 3.4 for Senate. Gap: 2.6 points

2012: Democrats by 6.9 for president and 5.6 for Senate. Gap: 1.3 points

2010: Republicans by 5.8 for governor and 4.8 for Senate. Gap: 1 point

2006: Democrats by 7.4 for governor and 37.8 for Senate. Gap: 30.4 points

2004: Democrats by 0.4 for president and 11.2 for Senate. Gap: 10.8 points

2000: Democrats by 0.2 for president and 24.5 for Senate. Gap 24.3 points.

1998: Republicans by 21 points for governor and Democrats by 2.2 for Senate. Gap 23.2 points.

1994:  Republicans by 36.4 for governor and Democrats by 17.6 points for Senate. Gap of 54 points.

As you can see from the numbers above, 2022 was the first “split outcome” between major races since 1998.  There was also a split outcome in 1994. But the last time it happened in a presidential year in Wisconsin — in other words, the last time the party that carried the state for president lost the Senate race on the same ballot — was 1968, 56 years ago.

You can also see from these numbers that the relationship between top races on the same ballot has varied a lot over time. Before 2010, big contests on the same ballot frequently differed by huge amounts.  That’s because ticket-splitting by individual voters was much more common. In 1994, GOP Gov. Tommy Thompson and Democratic Sen. Herb Kohl both won their races in landslides. Almost 40% of voters split their tickets.

But as the state polarized along party lines, ticket-splitting plunged to 6% or 7% in 2010 and 2012, and the top races on the ballot those years produced almost identical results.

More recently, though, ticket-splitting has bounced back a little, and we’ve seen bigger splits between top races in the same election cycle.

The most striking case is 2018, where Baldwin ran far ahead of fellow Democrat Evers. The nearly 10-point gap between those two races is a contemporary outlier, and probably not repeatable in a presidential year when voters are especially polarized.

But a gap of two or three or four points between Wisconsin’s two big races would not be strange or shocking.

And even a gap of one or two points could produce a split outcome, since the yearlong polling and the closeness of the last two presidential contests in this state suggest there will be very little separation between Trump and Biden here.

The current state of play — a 50/50 presidential race, and a small-to-modest lead for Democrats in the Senate race — suggests that two or three things must happen for Republicans to pick up Baldwin’s Senate seat.

First, Trump has to win Wisconsin.

Then either Hovde has to perform as well as Trump, or Trump has to carry this 50/50 state by a bigger margin than we saw in either 2016 or 2020, and create “coattails” big enough to bring Hovde along.

The modern history of Wisconsin is that the same party typically sweeps the big statewide election contests on the same ballot, and that could certainly happen again this November.

But you only have to look back two years to find an exception to that pattern.

Craig Gilbert provides Wisconsin political analysis as a fellow with Marquette University Law School's Lubar Center for Public Policy Research and Civic Education. Prior to the fellowship, Gilbert reported on politics for 35 years at the Journal Sentinel, the last 25 in its Washington Bureau. His column continues that independent reporting tradition and goes through the established Journal Sentinel editing process.

Follow him on Twitter: @Wisvoter.

This article originally appeared on Milwaukee Journal Sentinel: Tammy Baldwin posts stronger polling than Joe Biden in Wisconsin