---
title: "The growing Democratic domination of nation’s largest counties"
description: "In 2008, Barack Obama won 88 of the 100 largest U.S. counties; four years later he won 86 of them. The last time a Republican presidential candidate won more than a third of the 100 biggest counties was 1988."
date: "2016-07-21"
authors:
  - name: "Drew DeSilver"
    job_title: "Senior Writer/Editor"
    link: "https://www.pewresearch.org/staff/drew-desilver/"
url: "https://www.pewresearch.org/short-reads/2016/07/21/the-growing-democratic-domination-of-nations-largest-counties/"
---

# The growing Democratic domination of nation’s largest counties

[![](https://www.pewresearch.org/wp-content/uploads/sites/20/2016/07/FT_16.07.20_largestCounties.png)](https://www.pewresearch.org/short-reads/2016/07/21/the-growing-democratic-domination-of-nations-largest-counties/ft_16-07-20_largestcounties/)

Over the past few decades, Republicans and Democrats have become more and more sharply divided – not just ideologically, but also geographically. Democrats tend to do best in the nation's urban areas, while Republicans find their strongest support in [more rural areas](https://www.pewresearch.org/short-reads/2016/06/30/electorally-competitive-counties-have-grown-scarcer-in-recent-decades/). Now, a new Pew Research Center analysis of county-level presidential-voting data quantifies just how dominant Democrats are in big cities – and analysts say this dominance will present a [tough challenge to Donald Trump](http://www.theatlantic.com/politics/archive/2016/07/trump-and-the-city/491249/) this November.

In 2008 Barack Obama won 88 of the 100 most populous counties; in his re-election bid four years later he won 86. Given Obama's popularity among racial and ethnic minorities and young adults – who tend to cluster in big cities – that's not altogether surprising. But Democrats' urban dominance precedes Obama: The last time a GOP presidential candidate won more than a third of the 100 largest counties was 1988, when George H.W. Bush took 57 of them.

The disparity also is reflected in the parties' share of the big-county vote. As recently as 1988, they were essentially even: Bush took 49.7% of the total vote in the 100 largest counties, while Michael Dukakis took 49.2%. But the Republican vote share fell steeply in 1992 and never really recovered: Since then, George W. Bush was the only GOP presidential candidate to receive more than 40% of the vote in the 100 largest counties (in 2004). Meanwhile, Democrats' vote share in those counties has grown steadily, exceeding 60% in Obama's two races.

This wasn't always the case. Up to the 1990s, in fact, urban America was competitive territory for both Republican and Democratic presidential candidates: Ronald Reagan carried solid majorities of the 100 largest counties in both 1980 and 1984. In 2012, by contrast, Mitt Romney won only four counties with populations greater than 1 million: Maricopa County, Arizona; Orange County, California; Tarrant County, Texas; and Salt Lake County, Utah.

Most of the biggest counties have become more presidentially Democratic over the past four decades. We took a closer look at vote patterns in the 83 counties that were among the 100 most populous in both 1976 and 2012. In more than half (46 counties), the Democratic-Republican split shifted in the Democrats' favor by more than 20 percentage points; only nine became less Democratic to any degree.

[![](https://www.pewresearch.org/wp-content/uploads/sites/20/2016/07/FT_16.07.20_largestCounties_20shifts.png)](https://www.pewresearch.org/short-reads/2016/07/21/the-growing-democratic-domination-of-nations-largest-counties/ft_16-07-20_largestcounties_20shifts/)

For example, Illinois' DuPage County, a longtime GOP stronghold just to the west of Chicago, went for Gerald Ford by more than 40 percentage points in 1976 (68.8% to 28.3%). But it went for Obama twice, by nearly 11 percentage points in 2008 and by 1.1 percentage points in 2012.

One caveat is in order about Democrats' big-county advantage: Even as their grip on these counties has tightened, they carry less electoral heft than they used to. The 100 largest counties in 1976 together cast almost 44% of the total vote in that year's presidential election; in 2012, the top-100 vote share had slipped to 39.4%.

In recent decades Americans have increasingly [sorted themselves politically](http://www.jsonline.com/news/statepolitics/democratic-republican-voters-worlds-apart-in-divided-wisconsin-b99249564z1-255883361.html). A 2014 Pew Research Center report on [political polarization](https://www.pewresearch.org/politics/2014/06/12/section-3-political-polarization-and-personal-life/) found that liberals are about twice as likely as conservatives to live in urban areas, while conservatives are more concentrated in rural areas.