If a state is a red state, the voters within that state primarily vote for the Republican Party. If a state is a blue state, its residents mostly vote for the Democratic Party. The term red state is also used to describe a state perceived to have conservative views, while a blue state is understood to have more liberal views.
However, this hasn’t always been the case. During the 1980s, Democrats were associated with the color red, while Republicans were represented by the color blue. It was during the 2000 presidential election when journalist Tim Russert used the terms “red states” and “blue states” based on the colored maps that were used during his televised coverage. Since that time, media outlets have used red for Republican and blue for Democrat as the standard color scheme for their maps.
The measurement of how strongly a United States congressional district or state leans toward the Democratic or Republican Party compared to the nation as a whole is known as the Cook Partisan Voting Index (PVI). For example, if the national average is 51% Democratic, and the Democratic candidate of a state wins 62% of a two-party share, that state voted 11 percentage points more Democratic than the country, for D+11.
House balance gives a better indication of a party’s electoral strength in a state than basic party identification. It provides a definitive score that shows the strength of a party in an election. House balance takes into account the number of independents in a state. For example, California receives 55 electoral votes and has a house balance of 46D and 7R (53 out of 55).
According to Gallup tracking, there were 15 stable blue states in 2017. Those states are:
- New Jersey
- New Mexico
- New York
- Rhode Island
The same data show that four additional states lean toward being Democratic states. Those are:
Multiple states are split between Democrats and Republicans. Those states – the purple states, competitive states, or battleground states – include: