A purple state features roughly even numbers of Democratic and Republican supporters in a presidential election.
The purple state concept emerged from media usage of red to represent Republicans and blue to represent Democrats in electoral maps. The 2000 presidential election was the first occasion for the common use of the red and blue colors to indicate candidate support. From 2004 to present, closely divided states have been called purple states due to the mixture of red and blue.
Purple states are often called battleground states or swing states because of their importance to presidential candidates. In national elections, a majority of states are likely to go Democratic or Republican from the outset. This baked-in status leads to a rush by national campaigns to win purple state voters every four years.
Google Trends shows that “purple state” has been more consistently searched since 2004 than “battleground state” or “swing state.” There is a regular spike in “swing state” every presidential election but both terms took a back seat to “purple state” around the 2016 election.
The roster of swing states has expanded and contracted based on developments between elections. Southern Methodist University’s Center for Presidential History identified 11 purple states in the 2004 presidential election: Florida, Iowa, Michigan, Minnesota, Nevada, New Hampshire, New Mexico, Ohio, Oregon, Pennsylvania, and Wisconsin. The Washington Post named 10 battleground states in 2008 including Colorado, Indiana, Missouri, and Virginia. FiveThirtyEight identified up to 16 potential swing states in 2016 with new additions like Arizona, Georgia, and Maine.
As the concept of purple states emerged, there was a segment of political observers who disagreed with red and blue states. Professor Robert Vanderbei of Princeton University published maps starting with the 2000 election that used red and blue shades to indicate relative partisan support. Vanderbei argued that even his maps are misleading because they apply the same shades for metro areas and small towns without indicating population.
Proponents of the Purple America idea say that most voters across the country already live in purple states. This argument suggests that the average voter lives in a state with blue urban areas and red rural areas in conflict each election. Supporters of standard electoral mapping argue that red and blue states reflect the realities of presidential elections under the Electoral College.
London School of Economics (February 18, 2020): “Nevada became a US state in 1864, during the Civil War, giving it the motto ‘Battle Born.’ It is a battleground state politically, a ‘purple’ state.”
Vox (October 9, 2019): “But even if Texas isn’t a purple state, it is a gigantic state and therefore an important one. And the switch from R+20 to R+11 matters.”
The Pew Charitable Trusts (March 6, 2008): “Despite Obama’s strength in red-state caucuses and McCain’s appeal as a moderate, this analysis keeps the number of “purple” states – those neither safely red nor blue but still up for grabs – at its original 19, at least this stage of the most wide-open presidential contest in at least a half century.”