Red states and blue states

Starting with the 2000 United States presidential election, the term red state has been used to refer to states who predominantly vote for the Republican Party, and the term blue state has been used to refer to states who predominantly vote for the Democratic Party. By contrast, states where the predominant vote fluctuates between Democratic and Republican candidates are known as swing states or purple states.

Source: Wikipedia — Red states and blue states (CC BY-SA 4.0)