Recent changes in one of the most polarized places in America

More than a quarter of Wisconsin lives in Greater Milwaukee–the four counties of Milwaukee, Waukesha, Ozaukee, and Washington. While these places are inextricably linked economically, they are famously divided politically. Writing in 2014, Craig Gilbert observed that the Milwaukee metro area might be the most politically polarized of all major cities in America. Based on the 2012 election alone, it was certainly among the top few.1

Much political commentary and analysis since 2016 has focused on declining Republican margins2 in suburban areas. Citylab classified every Congressional district by density and found that Democrats in 2018 flipped the House of Representatives due to their suburban gains. They picked up 9 seats in “dense suburban” areas, 13 seats in “sparse suburban” districts, and 5 seats in places with a “rural-suburban mix.”3

Even though no seats flipped in Wisconsin, the state nonetheless saw many political changes. In fact, the median community changed its vote preference by 14% from Obama’s reelection in 2012 to Tony Evers’ election in 2018. The remainder of this post explores how the Trump era has affected partisanship in this most polarized part of Wisconsin.

A note on measurement

To control for the see-saw nature of politics, most of the statistics I present are the “relative margin,” which is the partisan vote minus the statewide lean. First, I calculate the area’s vote margin (% Democrat minus % Republican); then I subtract the statewide margin. For example, the City of Waukesha voted 42% for Evers and 56% for Walker, so its absolute margin is -14%. The state as a whole had a margin of +1%. So Waukesha’s relative margin is -15% because it voted 15% more Republican than the state as a whole.


Since 1990, the Greater Milwaukee Area combined has voted Democratic in 5 out of 7 Presidential elections and Republican in 7 out of 9 Gubernatorial races. In his first three elections, Scott Walker won the Milwaukee Area by 47,200; 44,900; and 47,900 votes, respectively. In 2018 he lost by 17,600 votes. Since Tony Evers only won statewide by 29,227 votes, you could say Walker’s deteriorating support in the Milwaukee area cost him the election.

So what changed? Let’s first examine the vote in three broad swathes of the Milwaukee Area which collectively hold 85% of the region’s population.

  1. The City of Milwaukee, home to 595,000 people or about 44% of the population.
  2. Milwaukee County’s 18 suburbs, home to 357,000 people–about 23% of the population.
  3. Waukesha County’s 38 suburbs, home to 401,000 residents, or about 30% of the total.

Each of these areas has followed a different trajectory over the last few decades.

Consider the pre-Trump era. From 1990 to 2014, the City of Milwaukee grew steadily more Democratic. By the 2010s, Democrats in Milwaukee were beating their statewide performance by more than 50 points. On the other extreme, Waukesha County grew steadily redder. In the early 1990s, it usually voted around 26 points more Republican than the rest of the state. By the 2012/2014 elections, this had increased to 40. The Milwaukee County suburbs began the ’90s around 7% more Republican than the state, but gradually moved closer to the state average.

The two elections of the Trump era suggest things have changed. In Milwaukee City support for Clinton was even higher relative to the state average than it was for Obama in 2012. Conversely, there was a slight decline in the Democrat’s relative performance between the governor’s race in 2014 and 2018.

The big changes happened in the suburbs. In 2012, the Milwaukee County suburbs voted 4% more Republican than the rest of the state. In 2016, they voted 11% more Democratic. The shift between gubernatorial races was smaller (1% more Republican in 2014 compared with 6% more Democratic in 2018) but similarly abrupt and consequential.

Waukesha County experienced a strikingly similar trend. In 2012 it voted 41 points more Republican than the state overall. In 2016 this fell to 26 points. Likewise, Waukesha voted 40% more Republican than the state in Walker’s 2014 reelection, but this fell to 35% in his 2018 defeat.

Pre-Trump vs Trump-era

To get a better sense of the overall shifts from the pre-Trump to the current Trump era of partisan politics, I generated two statistics. First, I calculated the average adjusted margin of the 2012 and 2014 elections for president and governor (left map). Then I found the same statistic for the following elections in 2016 and 2018 (middle map). The difference between these two numbers shows a durable shift toward the Democratic party across nearly all Milwaukee Area suburbs, but the size of this shift varies considerably (right map).