<P> Since the 2000 United States presidential election, red states and blue states have referred to states of the United States whose residents predominantly vote for either the Republican Party (red) or Democratic Party (blue) presidential candidates . Since then, the use of the term has been expanded to differentiate between states being perceived as liberal and those perceived as conservative . </P> <P> All states contain both liberal and conservative voters (i.e., are "purple") and only appear red / blue on the electoral map because of the winner - take - all system used by most states in the Electoral College . However, the perception of some states as "red" and some as "blue" was reinforced by a degree of partisan stability from election to election--from the 2000 election to the 2004 election, only three states changed "color", and as of 2016 fully 38 out of 50 states have voted for the same party in every presidential election since the red / blue terminology was popularized in 2000 . </P>

Where did red and blue states come from
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