This map depicts the partisan control of state governments. In states where one party has a "trifecta," that party controls the state's upper house, lower house, and governorship. Unlike every other state, Nebraska has a non-partisan legislature, and thus it is listed separately. All other states have divided government.
  Democrats retained trifecta  Democrats gained trifecta  Republicans retained trifecta  Republicans gained trifecta  Divided government maintained  Divided government established  Officially non-partisan legislature
Sources:

Conference of State Legislatures 2017 State &amp; Legislative Partisan Composition. Retrieved on January 11, 2018.[dead link]
2018 State &amp; Legislative Partisan Composition. NCSL. Archived from the original on 2018-11-08. Retrieved on 7 November 2018.
USStatecontrolpost2018.png
Source file: Orser67
This file: Pharexia (talk)