Primary Election Turnout in Midterms Since 2010

Elections

Primary elections in the United States are not uniformly administered. They do not all occur on the same date, have different rules for who may participate, have different rules for the number of candidates that can advance to the general election, and may or may not include a runoff election. When combined with variables such as incumbency and term limits, turnout in primaries can vary greatly by state and by year.

This page provides data on turnout in primary elections in three formats:

Table 1 Shows turnout in the last four midterm elections, calculated by dividing the total number of ballots cast in each state by its voting-eligible population.

Table 2 Shows the turnout difference between the primary and a subsequent runoff for the eight states that regularly hold runoffs during the last four midterm primaries.

Table 3 Categorizes the data in Table 1 by primary type to offer a clearer comparison of turnout by primary type.

NCSL chose to focus exclusively on state primaries during midterm election years because presidential years include presidential primaries that may or may not be held on the same date as state primaries, possibly skewing the data if those years were included.

This page is part of NCSL’s Toolkit for Primary Elections, which provides information on many different aspects of party nomination systems.

Table 1: Midterm Primaries Turnout Since 2010 (Total Ballots Cast/Voting-Eligible Population)
State	2010	2014	2018	2022
Alabama*	25.7%	19.0%	25.4%	24.3%
Alaska	33.7%	38.8%	22.9%	36.6%
Arizona	21.2%	18.8%	24.2%	28.6%
Arkansas*	22.7%	15.8%	14.8%	21.1%
California	23.3%	17.2%	26.1%	28.6%
Colorado	21.4%	16.1%	27.5%	28.1%
Connecticut	11.9%	3.8%	13.3%	7.9%
Delaware	14.9%	7.3%	18.1%	9.9%
Florida	20.5%	16.1%	25.2%	25.1%
Georgia*	17.2%	14.2%	15.8%	27.2%
Hawaii	32.8%	29.0%	28.2%	33.5%
Idaho	18.5%	16.9%	21.0%	23.6%
Illinois	18.9%	14.3%	22.4%	19.4%
Indiana	18.4%	12.6%	17.4%	13.3%
Iowa	13.1%	10.0%	12.1%	15.2%
Kansas	21.2%	16.6%	23.4%	47.7%
Kentucky	30.0%	26.8%	25.7%	22.4%
Louisiana**	N/A	N/A	N/A	N/A
Maine	32.1%	12.1%	26.4%	12.6%
Maryland	19.4%	17.0%	19.3%	23.8%
Massachusetts	14.6%	14.3%	19.5%	21.1%
Michigan	21.8%	17.4%	28.1%	28.5%
Minnesota	15.5%	9.8%	22.7%	19.1%
Mississippi*	4.3%	20.9%	12.6%	11.9%
Missouri	22.1%	23.0%	33.1%	23.9%
Montana	26.6%	27.4%	33.2%	33.7%
Nebraska	20.9%	23.7%	21.1%	29.8%
Nevada	18.4%	11.8%	15.5%	21.1%
New Hampshire	19.2%	15.6%	20.7%	21.9%
New Jersey	7.8%	6.5%	11.1%	12.3%
New Mexico	18.5%	13.0%	17.1%	17.2%
New York	9.0%	1.4%	2.8%	3.2%
North Carolina*	12.4%	14.3%	12.4%	18.3%
North Dakota	20.4%	16.8%	20.2%	18.6%
Ohio	20.3%	14.5%	18.4%	18.8%
Oklahoma*	20.5%	17.0%	32.5%	18.5%
Oregon	27.1%	25.2%	27.2%	34.6%
Pennsylvania	20.9%	13.2%	16.6%	28.9%
Rhode Island	16.3%	20.4%	19.2%	16.8%
South Carolina*	18.1%	12.5%	15.9%	14.3%
South Dakota	15.2%	16.7%	21.8%	28.5%
Tennessee	24.2%	21.2%	26.1%	18.6%
Texas*	14.4%	11.6%	14.8%	16.2%
Utah	12.6%	7.5%	16.5%	20.0%
Vermont	20.8%	7.7%	20.4%	25.5%
Virginia	2.9%	2.3%	9.2%	2.8%
Washington	29.9%	24.3%	32.1%	35.4%
West Virginia	18.2%	15.8%	21.3%	18.8%
Wisconsin	21.3%	14.6%	23.4%	27.9%
Wyoming	33.5%	28.0%	33.1%	42.3%

Source: Bipartisan Policy Center

*State uses primary runoffs for most offices.

**Because Louisiana uses an all-comers primary on the same day as other states’ general elections, it is not analogous to other states and is not included in this chart. For more information on primary systems, see NCSL’s State Primary Election Types page.

Table 2: Turnout Difference Between Primaries and Runoffs
State	2010		2014		2018		2022
	Primary	Runoff	Primary	Runoff	Primary	Runoff	Primary	Runoff
Alabama	25.7%	18.5%	19.0%	7.3%	25.4%	12.2%	24.3%	13.3%
Arkansas	22.7%	14.1%	15.8%	4.2%	14.8%	0.3%	21.1%	1.3%
Georgia	17.2%	10.9%	14.2%	9.1%	15.8%	10.0%	27.2%	5.4%
Mississippi	4.3%	0.3%	20.9%	20.2%	12.6%	3.2%	11.9%	7.5%
North Carolina	12.4%	3.1%	N/A	N/A	N/A	N/A	18.3%	2.5%
Oklahoma	20.5%	5.4%	17.0%	6.6%	32.5%	16.0%	18.5%	13.1%
South Carolina	18.1%	11.5%	12.5%	5.0%	15.9%	9.8%	14.3%	5.7%
Texas	14.4%	3.2%	11.6%	5.8%	14.8%	4.3%	16.2%	7.7%

Source: Bipartisan Policy Center

Table 3: Midterm Primaries Turnout by Primary Type
Open	Open
State	2010	2014	2018	2022
Alabama	25.7%	19.0%	25.4%	24.3%
Arkansas	22.7%	15.8%	14.8%	21.1%
Georgia	17.2%	14.2%	15.8%	27.2%
Hawaii	32.8%	29.0%	28.2%	33.5%
Idaho	18.5%	N/A	N/A	N/A
Michigan	21.8%	17.4%	28.1%	28.5%
Minnesota	15.5%	9.8%	22.7%	19.1%
Mississippi	4.3%	20.9%	12.6%	11.9%
Missouri	22.1%	23.0%	33.1%	23.9%
Montana	26.6%	27.4%	33.2%	33.7%
North Dakota	20.4%	16.8%	20.2%	18.6%
South Carolina	18.1%	12.5%	15.9%	14.3%
Tennessee	24.2%	21.2%	26.1%	18.6%
Texas	14.4%	11.6%	14.8%	16.2%
Vermont	20.8%	7.7%	20.4%	25.5%
Virginia	2.9%	2.3%	9.2%	2.8%
Wisconsin	21.3%	14.6%	23.4%	27.9%
Wisconsin	21.3%	14.6%	23.4%	27.9%

Partially Open
State	2010	2014	2018	2022
Illinois	18.9%	14.3%	22.4%	19.4%
Indiana	18.4%	12.6%	17.4%	13.3%
Iowa	13.1%	10.0%	12.1%	15.2%
Ohio	20.3%	14.5%	18.4%	18.8%
Wyoming	33.5%	28.0%	33.1%	42.3%

Open to Unaffiliated Voters
State	2010	2014	2018	2022
Arizona	21.2%	18.8%	24.2%	28.6%
Colorado	N/A	N/A	27.5%	28.1%
Massachusetts	14.6%	14.3%	19.5%	21.1%
New Hampshire	19.2%	15.6%	20.7%	21.9%
Rhode Island	16.3%	20.4%	19.2%	16.8%
New Jersey	7.8%	6.5%	11.1%	12.3%
Rhode Island	16.3%	20.4%	19.2%	16.8%

Partially Closed
State	2010	2014	2018	2022
Alaska	33.7%	38.8%	22.9%	N/A
California	23.3%	N/A	N/A	N/A
Connecticut	11.9%	3.8%	13.3%	7.9%
Idaho	N/A	16.9%	21.0%	23.6%
Maine*	32.1%	12.1%	26.4%	12.6%
Maryland	19.4%	17.0%	19.3%	23.8%
North Carolina	12.4%	14.3%	12.4%	18.3%
Oklahoma	20.5%	17.0%	32.5%	18.5%
Oregon	27.1%	25.2%	27.2%	34.6%
South Dakota	15.2%	16.7%	21.8%	28.5%
Utah	12.6%	7.5%	16.5%	20.0%
West Virginia	N/A	15.8%	21.3%	18.8%

Closed
State	2010	2014	2018	2022
Colorado	21.4%	16.1%	N/A	N/A
Delaware	14.9%	7.3%	18.1%	9.9%
Florida	20.5%	16.1%	25.2%	25.1%
Kansas	21.2%	16.6%	23.4%	47.7%
Kentucky	30.0%	26.8%	25.7%	22.4%
Nevada	18.4%	11.8%	15.5%	21.1%
New Jersey	7.8%	6.5%	11.1%	12.3%
New Mexico	18.5%	13.0%	17.1%	17.2%
New York	9.0%	1.4%	2.8%	3.2%
Pennsylvania	20.9%	13.2%	16.6%	28.9%
West Virginia	18.2%	N/A	N/A	N/A
State	2010	2014	2018	2022
California	N/A	17.2%	26.1%	28.6%
Washington	29.9%	24.3%	32.1%	35.4%

Multi-Party
State	2010	2014	2018	2022
Alaska	N/A	N/A	N/A	36.6%
California	N/A	17.2%	26.1%	28.6%
Nebraska	20.9%	23.7%	21.1%	29.8%
Washington	29.9%	24.3%	32.1%	35.4%

Source: Bipartisan Policy Center

*In 2022, Maine changed its system from Partially Closed to Open to Unaffiliated Voters, but the new system was not implemented in 2022.

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