This page contains information on the historical partisan composition of state senates. For more on the current partisan composition of state senates, click here.
In the partisan control charts below, state senates with a Democratic majority are encased in a blue ( ) box, while state senates with a Republican majority are encased in a red ( ) box. Tied senates, or those governed by a multipartisan coalition, are encased in a purple ( ) box.
Election breakdowns
Below is partisan composition data at the time of major elections.
2025 Elections
- See also: State legislative elections, 2025 and State legislative special elections, 2025
Heading into the 2025 elections, Democrats controlled 20 Senate chambers, Republicans controlled 29, and a bipartisan coalition controlled the Alaska Senate.[1]
- Senate chambers controlled by a Democratic majority: 20
- Senate chambers controlled by a Republican majority: 29[2]
- Senate chambers controlled by a bipartisan coalition: 1
2024 Elections
- See also: State legislative elections, 2024 and State legislative special elections, 2024
Heading into the 2024 elections, Democrats controlled 20 Senate chambers, Republicans controlled 29, and a bipartisan coalition controlled the Alaska Senate.[1]
- Senate chambers controlled by a Democratic majority: 20
- Senate chambers controlled by a Republican majority: 29[2]
- Senate chambers controlled by a bipartisan coalition: 1
2023 Elections
- See also: State legislative elections, 2023 and State legislative special elections, 2023
Heading into the 2023 elections, Democrats controlled 20 Senate chambers, Republicans controlled 29, and a bipartisan coalition controlled the Alaska Senate.[1]
- Senate chambers controlled by a Democratic majority: 20
- Senate chambers controlled by a Republican majority: 29[2]
- Senate chambers controlled by a bipartisan coalition: 1
2022 Elections
- See also: State legislative elections, 2022 and State legislative special elections, 2022
Heading into the 2022 elections, Democrats controlled 18 Senate chambers and Republicans controlled 32.[1]
- Senate chambers controlled by a Democratic majority: 18
- Senate chambers controlled by a Republican majority: 32[2]
2021 Elections
- See also: State legislative elections, 2021 and State legislative special elections, 2021
Heading into the 2021 elections, Republicans held a majority of state senate chambers. As of November 2021, 32 chambers were under GOP control, while Democrats held majorities in 18 chambers.[1]
- State chambers controlled by a Democratic majority: 18
- State chambers controlled by a Republican majority: 32[2]
2020 Elections
- See also: State legislative elections, 2020 and State legislative special elections, 2020
Heading into the 2020 elections, Republicans held a majority of state legislative chambers. As of November 2020, 59 chambers were under GOP control, while Democrats held majorities in 39 chambers.[1] A power-sharing agreement was established between Democrats and Republicans in the Alaska House of Representatives.
- State chambers controlled by a Democratic majority: 39
- State chambers controlled by a Republican majority: 59[2]
- One chamber with power sharing between the parties
2019 Elections
- See also: State legislative elections, 2019 and State legislative special elections, 2019
Heading into the 2019 elections, Republicans held a majority of state legislative chambers. As of November 2019, 61 chambers were under GOP control, while Democrats held majorities in 37 chambers.[1] A power sharing agreement was established between Democrats and Republicans in one chamber.
- State senates controlled by a Democratic majority: 18
- State senates controlled by a Republican majority: 32[2]
2018 Elections
- See also: State legislative elections, 2018 and State legislative special elections, 2018
Heading into the 2018 elections, Republicans held a majority of state legislative chambers. As of November 2018, 67 chambers were under GOP control, while Democrats held majorities in 32 chambers.[3]
- State senates controlled by a Democratic majority: 14
- State senates controlled by a Republican majority: 36
At the time of the 2018 elections, 1,948 state senators were affiliated with either the Republican or Democratic parties.
| Party
|
Number
|
Percentage
|
| Democratic state senators
|
830
|
42.1%
|
| Republican state senators
|
1,118
|
56.7%
|
| Independent state senators
|
4
|
0.2%
|
| Minor party state senators
|
3
|
0.2%
|
| Vacancies
|
17
|
0.9%
|
2017 Elections
- See also: State legislative elections, 2017 and State legislative special elections, 2017
Heading into November 2017, the Democratic Party held the majority in 13 state senates and the Republican Party held the majority in 37 senates. One state senate (Nebraska) was officially nonpartisan, but is held by a Republican majority.
- State senates controlled by a Democratic majority: 13
- State senates controlled by a Republican majority: 37[2]
At the time of the 2017 elections, 1,950 state senators were affiliated with either the Republican or Democratic parties.
| Party
|
Number
|
Percentage
|
| Democratic state senators
|
805
|
41%
|
| Republican state senators
|
1,145
|
58%
|
| Independent state senators
|
5
|
0.25%
|
| Minor party state senators
|
3
|
0.15%
|
| Vacancies
|
14
|
0.70%
|
2016 Elections
- See also: State legislative elections, 2016 and State legislative special elections, 2016
Heading into November 2016, the Democratic Party held the majority in 14 state senates and the Republican Party held the majority in 35 senates. One state senate (Nebraska) was officially nonpartisan.
- State senates controlled by a Democratic majority: 14
- State senates controlled by a Republican majority: 35
- State senates that were officially nonpartisan: 1
At the time of the 2016 elections, 1,904 state senators were affiliated with either the Republican or Democratic parties.
| Party
|
Number
|
Percentage
|
| Democratic state senators
|
818
|
41.4%
|
| Republican state senators
|
1,086
|
55.0%
|
| Nonpartisan state senators
|
49
|
2.48%
|
| Independent state senators
|
3
|
0.15%
|
| Minor party state senators
|
3
|
0.15%
|
| Vacancies
|
13
|
0.659%
|
2015 Elections
- See also: State legislative elections, 2015 and State legislative special elections, 2015
Heading into November 2015, the Democratic Party held the majority in 14 state senates and the Republican Party held the majority in 35 senates. One state senate (Nebraska) is officially nonpartisan.
- State senates controlled by a Democratic majority: 14
- State senates controlled by a Republican majority: 35
- State senates that are officially nonpartisan: 1
At the time of the 2015 elections, 1,908 state senators were affiliated with either the Republican or Democratic parties.
| Party
|
Number of
|
Percentage
|
| Democratic state senators
|
822
|
41.6%
|
| Republican state senators
|
1,086
|
55%
|
| Nonpartisan state senators
|
49
|
2.48%
|
| Independent state senators
|
2
|
0.10%
|
| Minor party state senators
|
1
|
0.05%
|
| Vacancies
|
12
|
0.60%
|
2014 Elections
- See also: State legislative elections, 2014 and State legislative special elections, 2014
Before the November 2014 elections, the Democratic Party held the majority in 18 state senates and the Republican Party held the majority in 31 senates. One state senate (Nebraska) is officially nonpartisan. Two state senates with numerical Democratic majorities (New York and Washington) were actually controlled by Republicans through a coalition. The overall score heading into the November 4 elections was:
- State senates controlled by a Democratic majority: 18
- State senates controlled by a Republican majority: 31
- State senates that are officially nonpartisan: 1
- See also: State senate elections, 2014
At the time of the 2014 elections, 1,901 state senators were affiliated with either the Republican or Democratic parties:
| Party
|
Number of
|
Percentage
|
| Democratic state senators
|
872
|
44.2%
|
| Republican state senators
|
1,029
|
52.1%
|
| Nonpartisan state senators
|
49
|
2.48%
|
| Independent state senators
|
4
|
0.2%
|
| Minor Party state senators
|
2
|
0.1%
|
| Vacancies
|
15
|
0.76%
|
2012 Elections
- See also: State legislative elections, 2012
Before the November 2012 elections, the Democratic Party held the majority in 19 state senates and the Republican Party held the majority in 28 senates. One state senate (Nebraska) is officially nonpartisan. Two state senates (Alaska and Virginia) were evenly divided between Democratic and Republican. Thus, the overall score heading into the November 6, 2012 elections was:
- State senates controlled by a Democratic majority: 19
- State senates controlled by a Republican majority: 28
- State senates that are officially nonpartisan: 1
- State senates that were tied: 2
- See also: State senate elections, 2012
At the time of the 2012 elections, 1,899 state senators were affiliated with either the Republican or Democratic parties:
| Party
|
Number of
|
Percentage
|
| Democratic state senators
|
872
|
44.2%
|
| Republican state senators
|
1,027
|
52.1%
|
| Nonpartisan state senators
|
49
|
2.5%
|
| Independent state senators
|
4
|
0.2%
|
| Minor Party state senators
|
2
|
0.10%
|
| Vacancies
|
8
|
0.4%
|
2010 Elections
- See also: State legislative elections, 2010
Before the November 2010 elections, the Democratic Party held the majority in 28 state senates and the Republican Party held the majority in 20 senates. One state senate (Nebraska) is officially nonpartisan. One state senate (Alaska) was evenly divided between Democratic and Republican senators but several Republicans in that senate vote with the Democratic caucus, so that functionally, the Alaska State Senate could be counted in the column of state senates where Democrats are in the majority. In that case, the overall score heading into the November 2, 2010 elections was:
- State senates controlled by a Democratic majority: 28
- State senates controlled by a Republican majority: 20
- State senates that are officially nonpartisan: 1
- See also: State senate elections, 2010
At the time of the 2010 elections, 1,913 state senators were affiliated with either the Republican or Democratic parties:
| Party
|
Number of
|
Percentage
|
| Democratic state senators
|
1,021
|
51.8%
|
| Republican state senators
|
892
|
45.3%
|
| Nonpartisan state senators
|
49
|
2.5%
|
| Independent state senators
|
4
|
0.2%
|
| Vacancies
|
5
|
0.2%
|
Current partisan composition
Alabama
- See also: Alabama State Senate, Alabama State Legislature
Alaska
- See also: Alaska State Senate, Alaska State Legislature
Arizona
- See also: Arizona State Senate, Arizona State Legislature
Arkansas
- See also: Arkansas State Senate, Arkansas State Legislature
California
- See also: California State Senate, California State Legislature
Colorado
- See also: Colorado State Senate, Colorado General Assembly
Connecticut
- See also: Connecticut State Senate, Connecticut State Legislature
Delaware
- See also: Delaware State Senate, Delaware State Legislature
Florida
- See also: Florida State Senate, Florida State Legislature
Georgia
- See also: Georgia State Senate, Georgia State Legislature
Hawaii
- See also: Hawaii State Senate, Hawaii State Legislature
Idaho
- See also: Idaho State Senate, Idaho State Legislature
Illinois
- See also: Illinois State Senate, Illinois State Legislature
Indiana
- See also: Indiana State Senate, Indiana State Legislature
Iowa
- See also: Iowa State Senate, Iowa State Legislature
Kansas
- See also: Kansas State Senate, Kansas State Legislature
Kentucky
- See also: Kentucky State Senate, Kentucky State Legislature
Louisiana
- See also: Louisiana State Senate, Louisiana State Legislature
Maine
- See also: Maine State Senate, Maine State Legislature
Maryland
- See also: Maryland State Senate, Maryland State Legislature
Massachusetts
- See also: Massachusetts State Senate, Massachusetts State Legislature
Michigan
- See also: Michigan State Senate, Michigan State Legislature
Minnesota
- See also: Minnesota State Senate, Minnesota State Legislature
Mississippi
- See also: Mississippi State Senate, Mississippi State Legislature
Missouri
- See also: Missouri State Senate, Missouri State Legislature
Montana
- See also: Montana State Senate, Montana State Legislature
Nebraska
- See also: Nebraska State Legislature
Nebraska Legislature is nonpartisan.
There are no formal party alignments or groups within the Nebraska State Senate. Coalitions tend to form issue-by-issue based on a member's philosophy of government, geographic background and constituency. However, almost all of the members of the legislature are affiliated with the state affiliate of either the Democratic or the Republican Party and both parties explicitly endorse candidates for legislative seats. Senators and candidates are listed as officially nonpartisan, but in most cases the individual has a direct party affiliation. As an example, in most cases if a sitting senator runs for Congress, the individual inevitably runs on a Democratic or Republican Party line. For more information on how Ballotpedia determined the partisan affiliation for Nebraska senators, please click here.
Nevada
- See also: Nevada State Senate, Nevada State Legislature
New Hampshire
- See also: New Hampshire State Senate, New Hampshire State Legislature
New Jersey
- See also: New Jersey State Senate, New Jersey State Legislature
New Mexico
- See also: New Mexico State Senate, New Mexico State Legislature
New York
- See also: New York State Senate, New York State Legislature
North Carolina
- See also: North Carolina State Senate, North Carolina State Legislature
North Dakota
- See also: North Dakota State Senate, North Dakota State Legislature
Ohio
- See also: Ohio State Senate, Ohio State Legislature
Oklahoma
- See also: Oklahoma State Senate, Oklahoma State Legislature
Oregon
- See also: Oregon State Senate, Oregon State Legislature
Pennsylvania
- See also: Pennsylvania State Senate, Pennsylvania State Legislature
Rhode Island
- See also: Rhode Island State Senate, Rhode Island State Legislature
South Carolina
- See also: South Carolina State Senate, South Carolina State Legislature
South Dakota
- See also: South Dakota State Senate, South Dakota State Legislature
Tennessee
- See also: Tennessee State Senate, Tennessee State Legislature
Texas
- See also: Texas State Senate, Texas State Legislature
Utah
- See also: Utah State Senate, Utah State Legislature
Vermont
- See also: Vermont State Senate, Vermont State Legislature
Virginia
- See also: Virginia State Senate, Virginia State Legislature
Washington
- See also: Washington State Senate, Washington State Legislature
West Virginia
- See also: West Virginia State Senate, West Virginia State Legislature
Wisconsin
- See also: Wisconsin State Senate, Wisconsin State Legislature
Wyoming
- See also: Wyoming State Senate, Wyoming State Legislature
See also
External links
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Although the Nebraska State Senate elects its members in nonpartisan elections, members of the chamber generally function along party lines when it comes to voting and caucusing. Please see Nebraska State Senate partisan affiliation for more information. Cite error: Invalid
<ref> tag; name "nebraska" defined multiple times with different content
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 Includes Nebraska, which is officially nonpartisan. For more information on how Ballotpedia determined the partisan affiliation of Nebraska senators, please click here. Cite error: Invalid
<ref> tag; name "NE" defined multiple times with different content
- ↑ Although the Nebraska State Senate elects its members in nonpartisan elections, members of the chamber generally function along party lines when it comes to voting and caucusing. Please see Nebraska State Senate partisan affiliation for more information.
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