NON-BIASED DEFINTION: In recent years, in the U.S. only, a red state has come to mean a state that traditionally votes
Republican, as opposed to a blue state which traditionally votes
Democrat.
In the past, media would use maps with red for one party and
blue for the other, with no set standard. The current trend was set during the 2000 Presidential election, when NBC used it. The race was very close, and because of this, Tim Russert was often heard to say things like "Bush needs x more red states in order to win, and Gore needs x more blue states in order to win." Because the coverage was being watched so intently by so many people, the color scheme stuck, and is now used by all networks.
What many people don't realize is that this color scheme is actually the opposite of traditional political colors. Red has always been associated with socialism and
communism (i.e. extreme forms of liberalism) as seen on flags of countries such as the P.
R.C., the U.S.S.R., and the D.P.R.K. On the other hand,
blue is most often associated with conservatism, and sometimes facism (i.e. the extreme form of conservatism). Most nations still use this color scheme.
It may be that NBC assigned these colors at
random, or it may be because
Republican and red both start with R. Neither party has officially adopted these colors. This color scheme has often led to confusion when residents of other countries see a political
map of the U.S. or hear Americans discussing red states versus blue states.