Since around the 2000 United States presidential election, red states and blue states have referred to states of the United States whose voters predominantly choose either the Republican Party (red) or Democratic Party (blue) presidential and senatorial candidates. Since then, the use of the term has been expanded to differentiate between states being perceived as liberal and those perceived as conservative. Examining patterns within states reveals that the reversal of the two parties' geographic bases has happened at the state level, but it is more complicated locally, with urban-rural divides associated with many of the largest changes.
