Lessons of 2018: Changing trends in Iowa's largest counties

Eighth in a series interpreting the results of Iowa’s 2018 state and federal elections.

Last week, Bleeding Heartland examined votes for governor in counties containing Iowa’s mid-sized cities, which collectively accounted for roughly 15 percent of Iowans who participated in this year’s election.

Today’s focus is ten counties where more than half of this year’s Iowa voters live. Whereas Fred Hubbell underperformed in all seventeen “micropolitan” areas, the results in larger counties were a mixed bag for the Democratic nominee.


Here are Iowa’s largest counties by population, with each county’s main city in parentheses.

Polk (Des Moines metro area)
Linn (Cedar Rapids metro area)
Scott (Iowa side of the Quad Cities)
Johnson (Iowa City metro area)
Black Hawk (Waterloo/Cedar Falls)
Woodbury (Sioux City)
Story (Ames)
Dubuque (Dubuque)
Pottawattamie (Council Bluffs)
Dallas (farthest-west suburbs of Des Moines)

The first table shows the total votes cast in each county for any candidate for governor, including write-ins. All numbers for this year’s election came from the Iowa Secretary of State’s results website on November 18. Eight counties had updated totals following the canvass; Linn and Scott still showed unofficial figures. NOVEMBER 25 UPDATE: The table now includes official totals from all counties. Linn numbers did not change, and the vote total increased by nine in Scott.

The counties appear in descending order from most to least votes cast in 2018. Turnout was higher in Dallas and lower in Woodbury relative to those counties’ population.

The electorate has grown in every county containing a large metro area, but the sharpest increases are in Dallas, Polk, Johnson, Linn, and Story counties, reflecting urban sprawl over the past couple of decades. In fact, Dallas was outside the top ten vote-producing counties in 1998, below four micropolitan counties (Cerro Gordo, Clinton, Marshall, and Jasper) and Warren County.

Votes cast for governor in Iowa’s largest counties
County 2018 2014 2010 2006 2002 1998
Polk 206,881 164,258 160,960 145,542 142,310 125,570
Linn 102,102 86,321 80,251 77,827 73,452 65,877
Scott 69,255 61,559 56,713 56,126 52,342 47,532
Johnson 68,107 52,238 51,725 44,010 38,622 33,691
Black Hawk 53,258 46,546 45,353 44,370 41,687 39,479
Story 42,824 32,845 32,337 29,881 28,611 24,956
Dubuque 42,760 36,295 33,910 33,797 32,277 27,628
Dallas 41,744 28,983 25,581 19,655 16,459 13,750
Woodbury 35,430 30,286 31,133 28,622 28,150 26,593
Pottawattamie 34,332 26,208 26,611 24,866 25,689 21,469
all 10 counties 696,693 565,539 544,574 504,696 479,599 426,545
share of statewide vote 52.5% 50.1% 48.5% 48.0% 46.8% 44.6%

Every county tallied more votes this year, no surprise given the highest statewide turnout for an Iowa midterm election since 1994.

Note the growing share of votes from population centers, relative to the state as a whole. Most Iowa counties have steadily lost residents for decades as economic growth has concentrated in a small number of metro areas and college towns. We can expect that trend to continue, so that each election cycle, the largest counties will provide an ever-higher share of total votes cast.

As more Iowans settle in urban or suburban neighborhoods, a Democratic candidate has more paths to win a statewide race without carrying dozens of counties, like Tom Vilsack and Chet Culver did in 1998, 2002, and 2006.

However, not every county with a large population consistently favors Democratic candidates.


Hubbell outpolled Governor Kim Reynolds by a historically wide margin in Iowa’s most urban counties.

How Fred Hubbell and Kim Reynolds performed in largest counties
County Hubbell votes Hubbell vote share Reynolds votes Reynolds vote share
Polk 120,257 58.1% 82,473 39.9%
Linn 56,767 55.6% 42,449 41.6%
Scott 35,147 50.7% 32,750 47.3%
Johnson 48,758 71.6% 18,119 26.6%
Black Hawk 29,259 54.9% 22,786 42.8%
Story 25,155 58.7% 16,535 38.6%
Dubuque 21,108 49.4% 20,532 48.0%
Dallas 19,804 47.4% 21,189 50.8%
Woodbury 15,024 42.4% 19,630 55.4%
Pottawattamie 14,234 41.7% 19,036 55.8%
all 10 counties 385,504 55.3% 295,499 42.4%

UPDATE: I put the same numbers into an interactive map. Click on any county for vote totals and percentages for Hubbell and Reynolds.

County Name

D Canidate 1 61% 30390
R Canidate 2 39% 10390

Hubbell above 70%

Hubbell between 50% and 60%

Hubbell won with less than 50%

Reynolds between 50% and 60%

This table compares Hubbell’s advantage or deficit in the largest counties with margins for Iowa’s only successful Democratic candidates for governor in the past 50 years.

Margin for Democratic candidates in largest counties
County Hubbell 2018 Culver 2006 Vilsack 2002 Vilsack 1998
Polk 37,784 21,075 20,377 24,133
Linn 14,318 14,510 10,508 10,782
Scott 2,397 8,754 4,178 -188
Johnson 30,639 17,135 11,901 11,880
Black Hawk 6,473 8,322 6,463 6,697
Story 8,628 4,517 4,975 4,491
Dubuque 576 7,431 6,300 4,369
Dallas -1,385 -704 422 1,049
Woodbury -4,606 -135 1,001 -305
Pottawattamie -4,802 -708 -907 -3,710
all 10 counties 90,022 80,197 65,218 59,198

Residents of Polk, Johnson, and Story delivered record victories for a Democratic nominee for governor or president. Even Barack Obama never came out of those counties with such a large advantage.

The Dallas County number is less bad than the trendline suggests. Given the massive growth of wealthy suburbs west of Des Moines, Hubbell did well to keep Reynolds’ margin so low. Republican candidates have carried this county by thousands of votes in the recent past.

Compared to Culver and Vilsack, though, Hubbell underperformed in other urban strongholds, particularly Dubuque, Scott, Woodbury, and Pottawattamie. Unofficial results show Reynolds received about 36,000 more votes statewide than her challenger. Hubbell could have made up a third of that margin by matching previous Democratic nominees’ results in Dubuque and not getting blown out in Woodbury and Pottawattamie.

This table shows the current political make-up of the largest counties, using statistics on active registered voters from the Secretary of State’s office, as of November 1. These figures do not take into account anyone who registered to vote on election day.

Voter registrations in Iowa’s largest counties (November 2018)
County registered voters Democrats Republicans no-party
Polk 291,285 116,906 (40.1%) 82,482 (28.3%) 88,764 (30.5%)
Linn 145,150 52,293 (36.0%) 38,164 (26.3%) 53,042 (36.5%)
Scott 115,337 35,821 (31.1%) 31,335 (27.2%) 47,264 (41.0%)
Johnson 94,461 44,754 (47.4%) 18,221 (19.3%) 30,540 (32.3%)
Black Hawk 82,207 30,130 (36.7%) 21,078 (25.6%) 30,164 (36.7%)
Story 61,882 20,348 (32.9%) 17,511 (28.3%) 23,177 (37.5%)
Dubuque 65,261 26,043 (39.9%) 16,223 (24.9%) 22,488 (34.4%)
Dallas 57,147 14,525 (25.4%) 19,996 (35.0%) 22,091 (38.7%)
Woodbury 57,746 17,862 (30.9%) 20,014 (34.6%) 19,422 (33.6%)
Pottawattamie 57,168 15,464 (27.1%) 21,147 (37.0%) 19,934 (34.9%)

In many ways, the results line up as we’d expect. For instance:

  • Reynolds carried the three largest counties where Republicans outnumber Democrats.
  • Hubbell did best in Johnson, which has the highest percentage of registered Democrats and the lowest percentage of Republicans.
  • The share of the vote for Hubbell and Reynolds was comparable in Linn and Black Hawk counties, which have similar proportions of Democrats, Republicans, and no-party voters.

On the other hand, some oddities stand out.

  • Hubbell did far better in Story than in Scott, which have comparable partisan breakdowns.
  • Hubbell’s share of the vote was higher in Dallas than in Pottawattamie or Woodbury, even though Democrats make up a higher percentage of the electorate in the latter two counties.
  • Hubbell underperformed in Dubuque, which has the third-highest percentage of Democrats in the electorate, after Johnson and Polk. We’d expect Polk to be a strong county for a candidate with deep family roots and connections in Des Moines. Even so, the small margin for Hubbell in Dubuque is noticeable and will increase Democratic anxiety that Donald Trump’s victory in this solid blue county was no fluke.

Since voter registration numbers don’t fully explain the disparate election outcomes, I pulled together some other statistics that struck me as potentially relevant. Most of the information in the next table comes from U.S. Census Bureau data as of July 2017. The unemployment column draws on Iowa Workforce Development numbers from September 2018.

Demographic, economic statistics in Iowa’s largest counties
County white, not Latino adults w/college degree median household income unemployment rate poverty rate under age 18 over age 65
Polk 77.6% 35.6% $61,684 2.2% 10.9% 25.0% 12.7%
Linn 86.1% 32.2% $60,989 2.4% 10.0% 23.5% 15.4%
Scott 85.9% 31.9% $56,454 2.6% 13.4% 23.9% 15.8%
Johnson 83.6% 52.4% $56,808 1.7% 17.0% 20.2% 11.2%
Black Hawk 81.6% 27.0% $50,348 2.4% 16.1% 21.7% 16.0%
Story 83.5% 50.3% $51,201 1.4% 19.2% 16.5% 11.6%
Dubuque 90.7% 29.2% $56,154 1.9% 10.5% 23.1% 17.4%
Dallas 85.5% 47.4% $78,918 1.6% 4.9% 28.1% 11.8%
Woodbury 73.3% 21.7% $49,010 2.1% 13.3% 26.2% 14.7%
Pottawattamie 87.7% 20.7% $53,260 2.0% 10.3% 23.7% 16.9%
State of Iowa 85.7% 27.2% $54,570 2.1% 10.7% 23.3% 16.7%

We see evidence of the widening partisan split among white voters, depending on education level. The best counties for Hubbell (Johnson and Story) have the highest share of Iowans with a college degree. The high percentage of college-educated Dallas County residents is likely the primary reason Reynolds fared worse there than one would guess base on the GOP voter registration advantage.

Conversely, the best large-population counties for Reynolds were Pottawattamie and Woodbury, which have relatively low numbers of college-educated adults.

Hubbell’s best counties had a younger population on the whole, with a smaller percentage of senior citizens.

In other respects, this table raises more questions than answers for me.

  • Why didn’t Hubbell do better in Dubuque? That county has more college-educated voters as well as a higher percentage of registered Democrats than Black Hawk, yet Hubbell carried Black Hawk by 12 points and Dubuque by less than 1.5 points.

    Is the Waterloo area’s greater racial diversity in the main explanatory factor? Or did Reynolds benefit from the national trend of white Catholics “drifting toward the Republican Party”? (I don’t have current statistics on the religious identities of Iowans, but Dubuque is among the most heavily Catholic counties.) Some Hubbell campaign commercials and direct mail pieces highlighted his longstanding support for Planned Parenthood, which could have backfired in this area.

  • Linn and Scott counties are similar in terms of racial breakdown, education level, and percentage of senior citizens, so why did Hubbell win by 14 points in Linn but only by a little more than 3 points in Scott?
  • Democrats often have better results in more racially diverse areas, yet Hubbell’s vote share better in Woodbury (the least white county on this list) was only a tiny bit higher than in Pottawattamie (the second most white of Iowa’s large urban counties).
  • Median income, unemployment, and poverty levels do not appear to be correlated with voting patterns in these counties. Does that mean “it’s not the economy, stupid”?
  • Higher-income Americans have historically favored Republican candidates. Will Democrats consolidate their gains among well-off suburbanites in Polk, Dallas, and Linn counties, or will this year be an anomaly because Trump repels so many college-educated voters?

Any relevant questions or insights are welcome in this thread.

Top image: On left, the main Polk County administrative office building in Des Moines. On right, Davenport City Hall in Scott County.

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  • Two things

    I suspect that Hubbell’s Planned Parenthood ads did indeed hurt him in Dubuque County, unfortunately. I hope someone will look into that.

    And as a side note, thank you for using the accurate term “urban sprawl.” It can be surprisingly difficult to get elected officials to acknowledge that urban sprawl really is happening in Iowa, even when those officials are Democrats.

    • I learned today

      that the Hubbell campaign ran some Planned Parenthood-themed radio ads on conservative stations in Sioux City. If true, that is malpractice.

  • College towns...

    could potentially explain most of the disparities between Scott and Linn, and even Black Hawk and Dubuque (though the PP mailer is likely more to blame), and would certainly explain how Story was carried so strongly.

    The GOTV and registration drives on college campuses and by groups like Next Gen Climate could be a big part of it. December would be a good time to look back on some of the county’s websites and/or the SoS website to see if demographic participation numbers are posted, which may show higher young adult turnout in those counties.

    Turnout percentages (based on Gubernatorial votes divided by Registered voters) also show “poor” turnout (relatively speaking) in Scott, Woodbury, and Pottawattamie counties (all < 62%); Black Hawk and Dubuque had 64 and 65%, and the rest 69-73%. The question then might be "why didn't D's show up in Scott, Woodbury, or Pottawattamie?" What was (or wasn't) down-ballot in those counties?

    • college towns

      have a higher proportion of people with college degrees, so that’s where you are seeing the effect.

      Relatively low turnout in Scott, Pottawattamie, and Woodbury counties is a longstanding problem for Iowa Democrats. If you look at past election results there, you will consistently find fewer votes cast in state House and Senate races than in many other districts around the state. I don’t know why it happens.

  • Don't get me started...

    We know we have a problem, Houston, and it’s called the “coordinated campaign” — otherwise known this year as the Campaign for Iowa. We also have too many people in decision-making positions who don’t listen and don’t respond. I suspect it goes back to the money: the people who pony up the money tell us who to hire, and the consultants give us cookie-cutter, tone-deaf public messaging.