A (Recent) History of Partisan Control of State Legislatures

UPDATE 12/7/2021: I have recently written and self-published my own book! It’s called Why Independents Rarely Win Elections: And How They Could Become More Competitive. It is a comprehensive look at the reasons why independent candidates for elected office have such a tough time being successful, and provides some practical measures that can be taken to make them more viable in elections. You can buy it here at Amazon as an ebook or paperback! And if you enjoy it, please leave a review!

Image Source: Governing. “‘Not Exactly a Blowout’: Democrats Score Modest Gains in State Legislatures.” http://www.governing.com/topics/politics/gov-democrats-state-legislatures-2018-midterm-elections-trump.html

Congress and its dealings, most notably the partisan wrangling, may get the most scrutiny and coverage in the news, but state legislatures are also highly important. There are a lot of issues that they handle that Congress doesn’t, are inherently closer physically to their constituents than Congress, and most of them exert a lot of power over state legislative and congressional redistricting, just to name a few roles state legislatures play.

As much as the focus is on which party controls one or both chambers of Congress, which parties control which state legislatures and chambers is also quite intriguing. Some of the “blue wave” predictions came to fruition in 2018, and it wasn’t just Democrats taking control of the U.S. House. They also made large gains in state legislatures, although Republicans still control more than Democrats in this regard.

One of the ways that party control of a state government (not just state legislatures) can be studied is through Ballotpedia’s term of “state government trifectas.” The basic meaning of a trifecta is when one party controls both legislative chambers and the governorship of a state, although the term can also be expanded to include whether the highest court of a state often sides with the political party in power or whether the ruling party has supermajorities in both legislative chambers.¹

Of course, having majorities in both legislatures doesn’t guarantee control of the governor’s office. Wisconsin, for example, just had its trifecta broken this year. While the Republican Party kept firm control of both Wisconsin’s State Assembly (House) and its State Senate, incumbent Republican governor Scott Walker lost a close race to Democrat Tony Evers. Nevertheless, a party’s control of both chambers of a state legislature usually means control of the governor’s office as well.

The focus today, however, is specifically on state legislatures. The National Conference of State Legislatures (NCSL) has data on state legislative partisan compositions for at least over the past 40 years. The information from NCSL studied in this article shows which party controlled a state legislature in January of even-numbered years, or if the chambers were split between both parties. The NCSL has charts broken up into the following periods: 1978–1988, 1990–2000, and 2002–2014. As such, there will be three sections following that convention. Ballotpedia will be the primary source for the years since then, although they also have data on state legislatures in some of the timeframes that NCSL covers.

Some states have been very resistant to change in partisan control. Hawaii has been a Democratic stalwart since at least 1978 (today, the Democratic Party is so dominant in the state that they control 70 of the 76 total state legislative seats). Meanwhile, Wyoming’s state legislature has been steadfastly Republican since at least 1978 (currently, the Republican Party in the state holds a commanding 78 of the 90 total state legislative seats). Other states have shown more propensity to change.

1978–1988: Democratic Dominance

Source: NCSL. “Partisan Composition of State Legislatures 1978–1988.”

While Republicans have the upper hand in total state legislative members today, Democrats were once the dominant party. Between 1978 and 1988, 22 state legislatures stayed under Democratic control throughout that entire time, including some states that we now routinely associate with Republicans. These 22 states were Alabama, Arkansas, California, Connecticut, Florida, Georgia, Hawaii, Kentucky, Louisiana, Maryland, Massachusetts, Mississippi, Missouri, North Carolina, Oklahoma, Oregon, Rhode Island, South Carolina, Tennessee, Texas, Virginia, West Virginia, and Wisconsin.²

In contrast, only seven states stayed with Republicans for that whole period of time: Arizona, Colorado, Idaho, Kansas, South Dakota, Utah, and Wyoming. (Indiana almost was part of this group, but the Republican and Democratic Parties each controlled one of its legislative chambers in 1988.) While Democrats held both chambers of a state legislature at least one time for 35 states, Republicans did the same for only 15 states.²

Some states were competitive, however. Alaska and New York were the only states that had split legislatures throughout all of 1978 through 1988, but there were other states that often had divided legislatures. With the exception of 1980 under Republican control, Pennsylvania's legislature was split every time. Minnesota and Ohio were always split save for two periods in each state where Democrats took control of both chambers in those states (1982 and 1988 in Minnesota, 1978 and 1982 in Ohio). In total, 17 states had at least one time where the state legislature was split between the two parties.²

Nevertheless, Democrats clearly were the more prevalent force at the state legislative level overall. But that was about to change in the next decade.

1990–2000: The Partisan Tide Shifts

Source: NCSL. “Partisan Composition of State Legislatures 1990–2000.”

Cracks in the Democratic state legislative foundation became noticeable in the last decade of the 20th century. The NCSL’s chart for 1990–2000 noticeably shows a lot more red (Republican) than its chart for 1978–1988. There were also considerably more instances of split legislatures. Only 16 states had been controlled by Democrats for the whole decade. While the same was true of only two states for Republicans, some previously Democratic strongholds became consistently split or in Republican control. In 30 states, state legislatures were split at least once, with four of them being that way for the whole decade (Delaware, Indiana, Nevada, and New York). Eleven states in this decade were always under either Republican control or split between the parties.³

While Republicans had made clear inroads in state legislatures, Democrats still more often held control overall. The 21st century would change that.

2002–2014: The Republican Surge

Source: NCSL. “Partisan Composition of State Legislatures 2002–2014.”

If states that we now consider Republican did not reflect that perception in state legislatures at the turn of the millennium, they certainly would after it. There were 11 states that stayed entirely under Republican control for this whole time period, while this was the case for Democrats in only nine states. Democrats would not have full control of a state legislature at any time for 19 states, while the same was true for Republicans in 16 states. States had split legislatures for at least one point in this time frame in 23 states. In 2014, 26 state legislatures were under Republican control, 19 state legislatures were under Democratic control, and 4 state legislatures were split between the two parties. (Nebraska has been unicameral and nominally nonpartisan since the 1930s, so it has not been included in any of these measures).⁴

That being said, this period of time wasn’t completely favorable to Republicans. Democrats still had more unified control of state legislatures in 2006 and especially 2008 and 2010 than Republicans did. Still, Republicans completely flipped the script in 2012, leading to their upward trend since.

State Legislatures in 2016 and 2018

The trend of state legislative control continued in the 2016 election in favor of Republicans. They came to control 32 legislatures while Democrats only controlled 14 legislatures, with only 3 legislatures being split.⁵ This was the most state legislatures Republicans had unified control of at any point in time at least since 1978 and is possibly the most state legislatures they have ever held at one time.

As discussed at the beginning of this article, however, Democrats found some success in reversing this trend as part of the “blue wave” predictions for 2018. The number of Republican-controlled states was whittled down slightly to 30, but Democrats gained unified control of four more legislatures to make their total 18.⁶ Only one state legislature, Colorado, has a split legislature, with its Senate belonging to Republicans and its House belonging to Democrats.⁷ (There are a couple caveats to note. Connecticut’s State Senate is actually evenly divided between the two parties at 18 apiece. Alaska is also technically split because — although there are more Republicans than Democrats in their state house — a coalition between the Democrats, three Republicans, and two independents effectively gives majority control of Alaska’s State House to the Democratic Party. Here, however, Alaska is considered to be unified under Republicans.)⁷

Where Does State Legislative Partisan Composition Go From Here?

Below is a visual for partisan control of state legislative chambers from 1978–2016, along with the number of U.S. Senate and U.S. House members for comparison.

Image Source: Nick Hillman. University of Wisconsin-Madison. “Party control in Congress and State Legislatures (1978–2016).” https://web.education.wisc.edu/nwhillman/index.php/2017/02/01/party-control-in-congress-and-state-legislatures/ (accessed January 3, 2019).

Adding the 2018 numbers, at this point, it’s impossible to tell if the slight setback for Republicans in state legislatures is part of a trend of reversal in their recent fortunes or simply an aberration. While part of it is undoubtedly anti-Trump sentiment, it isn’t clear what all the factors in play are. The sitting president’s party has always lost a lot of their state legislative seats at least since Franklin Roosevelt’s administration (with the exception of Ronald Reagan, but even then the Republican Party only gained a total of six seats).⁸

Image Source: Ballotpedia. “State legislative elections, 2016.” https://ballotpedia.org/State_legislative_elections,_2016https://ballotpedia.org/State_legislative_elections,_2016 (accessed January 3, 2019).

In this context, the Republican Party seems to also be heading for another stretch of bumpy road in the 2020 state legislative elections. Still, it's hard to imagine that Democrats will come close to even with Republicans in how many state legislatures each has unified control over in the near future, even if this is the start of a trend in favor of Democrats.

Yet politics always comes up with surprises. Perhaps the next few elections will have some in store for the never-ending partisan battles for state legislative control.

  1. Ballotpedia. “State government trifectas.” https://ballotpedia.org/State_government_trifectas (accessed January 2, 2019).
  2. NCSL. “Partisan Composition of State Legislatures 1978–1988.” http://www.ncsl.org/documents/statevote/legiscontrol_1978_1988.pdf (accessed January 3, 2019).
  3. NCSL. “Partisan Composition of State Legislatures 1990–2000.” http://www.ncsl.org/documents/statevote/legiscontrol_1990_2000.pdf (accessed January 3, 2019).
  4. NCSL. “Partisan Composition of State Legislatures 2002–2014.” http://www.ncsl.org/documents/statevote/legiscontrol_2002_2014.pdf (accessed January 3, 2019).
  5. Nick Hillman. University of Wisconsin-Madison. “Party control in Congress and State Legislatures (1978–2016).” https://web.education.wisc.edu/nwhillman/index.php/2017/02/01/party-control-in-congress-and-state-legislatures/ (accessed January 3, 2019).
  6. NCSL. “State Partisan Composition.” http://www.ncsl.org/research/about-state-legislatures/partisan-composition.aspx (accessed January 3, 2019).
  7. Ballotpedia. “Partisan composition of state legislatures.” https://ballotpedia.org/Partisan_composition_of_state_legislatures (accessed January 3, 2019).
  8. Ballotpedia. “State legislative elections, 2016.” https://ballotpedia.org/State_legislative_elections,_2016https://ballotpedia.org/State_legislative_elections,_2016 (accessed January 3, 2019).

Self-Published Author; Sayfie Review & Ballotpedia (my views do not express those of my employers); M.A. in Political Science (UF Political Campaigning program)