Ballotpedia is concluding its analysis of Pivot Counties in the 2020 presidential election with a look at the presidential margins of victory in these counties and how they have changed over time.

Pivot Counties are the 206 counties nationwide that voted for Barack Obama (D) in 2008 and 2012 and Donald Trump (R) in 2016.

In 2020, we have used the following categories to describe these counties:

• Retained Pivot Counties, which voted for Trump again this year, and 
• Boomerang Pivot Counties, which voted for Joe Biden (D) on Nov. 3.

Following the 2020 presidential election, there were 181 Retained Pivot Counties and 25 Boomerang Pivot Counties.

In 2008, Obama had an average margin of victory of 12.3 percentage points across all 206 of these counties. In 2020, the average result across all Pivot Counties was a win for Trump by a margin of 12.8 percentage points. This represents a shift of 25.1 percentage points towards Republicans.

When looking at just the 181 Retained Pivot Counties, the margin shift from 2008 increases to 26.2 percentage points. Of those 181 counties, Trump won a larger margin of victory in 113 compared to his 2016 results. Trump’s margin decreased in 68 Retained Pivot Counties.

The average margins in the 25 Boomerang Pivot Counties Joe Biden (D) won in 2020 shifted 10.2 percentage points towards Republicans when compared to results from the same counties in 2008.

The chart below shows the overall change in average margins of victory by Pivot County category between 2008 and 2020. 

The table below shows the margins of victory from each presidential election since 2008 using the categories above. The rightmost section shows the total change since 2008 both in percentage points and percent change. In Retained Pivot Counties, the average margin of victory has shifted 217% towards Republicans. In the 25 Boomerang Pivot Counties that voted for Biden, the average margin has shifted 76% towards Republicans.

The Pivot Counties where Trump’s margin of victory increased from 2016 were located primarily in the Southeast and Upper Midwest, concentrated in states like Iowa, Illinois, Wisconsin, and Minnesota. Counties where Trump’s margin decreased in 2020 were located primarily in New England and the Northeast.

Woodruff County, Ark., a Retained Pivot County, had the largest margin change towards Trump in 2020 with an 18.8 percentage point shift. Ziebach County, S.D., a Boomerang Pivot County, had the largest margin change towards Biden with a 10.5 percentage point shift.

The map below does not differentiate between Retained and Boomerang Pivot Counties. Instead, it shows counties based on whether their margins of victory became either more Republican, towards Trump, or more Democratic, towards Biden, compared to 2016 results.

To learn more about 2020 presidential election margins of victory in Retained and Boomerang Pivot Counties, click here: Election results, 2020: Pivot Counties’ margins of victory analysis