Political party strength in U.S. states

Political party strength in U.S. states is the level of representation of the various political parties in the United States in each statewide elective office providing legislators to the state and to the U.S. Congress and electing the executives at the state (U.S. state governor) and national (U.S. President) level. == History == Throughout most of the 20th century, although the Republican and Democratic parties alternated in power at a national level, some states were so overwhelmingly dominated by one party that nomination was usually tantamount to election.

Source: Wikipedia — Political party strength in U.S. states (CC BY-SA 4.0)