Ballotpedia:Who Runs the States, Partisanship Results, Partisan Control of State Legislatures
The two major political parties claim that their policies will lead to better outcomes. What does the data show?
At Ballotpedia, we explored these issues in a three-part study, Who Runs the States.
This page contains the section of the report pertaining to the Partisan Control of State Legislatures.
Partisan Control of State Legislatures
A bit more than half as many states had periods of both Democratic and Republican legislative control as had both Democratic and Republican governors from 1992 to 2013. Although 46 states had at least one governor from each major party, only 25 state legislatures were controlled for at least one year by each party. We classified a state legislature as being under a political party’s control when that party had majorities or at least functional control (due a tie-breaking lieutenant governor or coalitions with allied legislators outside of the party) in both legislative chambers. If different parties controlled a state’s senate and its house of representatives, or if one chamber was tied or governed according to a power sharing agreement, that legislature was classified as being under split control. For information about ties and power sharing, see Appendix B.
On average across the 22 years surveyed, the United States had 37.6 legislatures under single-party control (20.1 Democratic and 17.5 Republican) and 11.4 legislatures under split partisan control, and 1 nonpartisan legislature. Nebraska is the only state in the nation to have a unicameral (single-chamber) legislature and also the only state to have a nonpartisan legislature that is neither elected nor formally organized along party lines. The remainder of this analysis of the partisan control of state legislatures and trifectas excludes Nebraska and deals only with the 49 states which have partisan legislatures. The average partisan state legislature was under Democratic control for 9 of 22 years (41.1 percent), under Republican control for 7.8 years (35.6 percent), and under split partisan control for 5.1 years (23.3 percent). During the 22 years, 21 state legislatures were under Democratic control more frequently than they were under Republican or split partisan control, 19 were most often under Republican control, and 8 were typically under split control. New Jersey’s legislature was Republican for 10 years, Democratic for 10 years, and split for 2 years.
Over the past 22 years, state legislatures have come increasingly under single-party control. In 1994, the year with the lowest level of single-party legislative control in our study, 32 legislatures were under single-party control. During the first 11 years (1992-2002), the 49 partisan state legislatures were under single-party control 72.5 percent of the time. About 57 percent of the single-party state legislatures were under Democratic control, while Republicans controlled 43 percent. In the final 11 years (2003-2013), partisan state legislatures were under single-party control 81 percent of the time. Of the single-party state legislatures, 50.2 percent were controlled by Democrats and 49.8 percent by Republicans. In 2009, the number of legislatures with single-party control reached 40 for the first time in our study and stayed the same or increased in each year through 2013, when 44 of 49 partisan state legislatures are under single-party control.
In comparing the two 11-year periods, we found that the proportion of the 49 partisan legislatures under single-party control increased by 8 percent, from 73 to 81 percent. This trend of increasing single-party control of state legislatures has continued despite several recent national swings of control between the major parties, holding true after Democratic gains in 2008, the Republican landslide in 2010, and Democratic gains in 2012.
Thirteen states did not have a Republican legislature for even one year. Six of these legislatures (Connecticut, Delaware, Kentucky, Nevada, New York, and Vermont) had a combination of Democratic and split control, and the other seven (California, Hawaii, Maryland, Massachusetts, New Mexico, Rhode Island, and West Virginia) were under Democratic control for the entire period. Of the 21 states which had Democratic legislatures more often than Republican or split ones, 12 had Democratic legislatures more than 80 percent of the time. The Democrats controlled their greatest number of state legislatures in 1992 with 29, the highest number recorded by either party. They approached this figure in 2009 and 2010 when they controlled 27 legislatures but thereafter controlled their lowest number of legislatures in 2011 and 2012 with only 15. Eleven state legislatures were not under Democratic control for even one year. Eight (Alaska, Arizona, Indiana, Kansas, Michigan, North Dakota, Ohio, and South Dakota) had a combination of Republican and split control, and the other three (Idaho, Utah, and Wyoming) were entirely under Republican control. Of the 19 states which had Republican legislatures more often than Democratic or split ones, 7 had Republican legislatures more than 80 percent of the time. Republicans controlled only seven legislatures in 1992, the fewest within this time frame. In 2012, they controlled their greatest number of state legislatures with 28.
All 49 partisan state legislatures had some years of single-party control. The New York legislature was the closest of any state legislature to having permanent split partisan control, with split control for 20 of the 22 (91 percent) years studied. No state legislature was under independent or minor-party control during this period. The last time a state legislature was under even plurality control of a minor party was in 1938, the fourth and final year of the Progressive Party’s dominance in Wisconsin politics.
- Ballotpedia:Who runs the states
- Ballotpedia:Who Runs the States, Part One: State Partisanship
- Full report PDF
- State government trifectas
- Alabama, Arkansas, Colorado, Florida, Georgia, Illinois, Iowa, Louisiana, Maine, Minnesota, Mississippi, Missouri, Montana, New Hampshire, New Jersey, North Carolina, Oklahoma, Oregon, Pennsylvania, South Carolina, Tennessee, Texas, Virginia, Washington, and Wisconsin.