Ballotpedia:Who Runs the States, Partisanship Results, Methodology
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 report methodology.
We identified partisan control of each state’s governorship and legislature for each year from 1992 through 2013. To identify the partisan control of each state’s governorship, we used lists of each state’s governors from official and media sources and determined the partisan affiliation of the governor or governors who held the office for the majority of each year. For each year, each state’s governorship was coded as Republican, Democratic, or Other.
To identify partisan control of each state legislature, we used the data found in Michael J. Dubin’s Party Affiliations in the State Legislatures: A Year by Year Summary, 1796-2006 (McFarland, 2007) for the years from 1992 through 2006. We used official and media sources for the years from 2006 to 2013. We cross-checked our data for the years through 2011 with the legislative partisan balance data compiled by Indiana State University’s Dr. Carl Klarner. When one party had majority control in both legislative chambers for most of a given year, the legislature was coded as Democratic or Republican. For example, the North Carolina legislature flipped from Democratic to Republican control after the 2010 election. We coded North Carolina as a Democratic legislature in 2009 and 2010, but Republican in 2011 and 2012. We also identified legislatures as under Split Control when one legislative chamber was run according to a bipartisan power-sharing agreement or by a bipartisan coalition instead of the regular party leadership. Examples include the Virginia Senate in 1995 and 1996 and Oregon House of Representatives in 2009 and 2010. When each party controlled one chamber, the legislature was coded as being under “Split Control.” Nebraska’s single-chamber, nonpartisan legislature was coded as Nonpartisan for the entire 22-year period.
We then combined our gubernatorial and legislative partisanship data to determine during which years, if any, each state government had had a trifecta. When both its governorship and legislature were controlled by the same party, a state was coded as having either a Republican or a Democratic trifecta. When its governorship and legislature were controlled by different parties or when the legislature was under split control, a state was coded as having Divided Government. We did not include Nebraska in the trifecta calculations because of its nonpartisan legislature.
- Ballotpedia:Who runs the states
- Ballotpedia:Who Runs the States, Part One: State Partisanship
- Full report PDF
- State government trifectas
- Klarner, Carl, William Berry, Thomas Carsey, Malcolm Jewell, Richard Niemi, Lynda Powell, and James Snyder, State Legislative Election Returns (1967-2010), ICPSR34297-v1, Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor, 2013-01-11. doi:10.3886/ICPSR34297.v1.]