Entry in progress—B.P.
 
A purple state is also called a “battleground state” and a “swing state.”
 
Wikipedia: Red states and blue states
The terms “red states” and “blue states” came into use in 2000 to refer to those states of the United States whose residents predominantly vote for the Republican Party or Democratic Party presidential candidates, respectively. A blue state tends to vote for the Democratic Party, and a red state tends to vote for the Republican Party, although the colors were often reversed or different colors used before the 2000 election. According to The Washington Post, the terms were coined by television journalist Tim Russert during his televised coverage of the 2000 presidential election; that was not the first election during which the news media used colored maps to graphically depict voter preferences in the various states, but it was the first time a standard color scheme took hold. Since 2000, usage of the term has been expanded to differentiate between states being typically liberal and those typically conservative.
 
This unofficial system of political colors used in the United States is the reverse of that in most other long-established democracies, where blue represents right-wing and conservative parties, while red represents left-wing and socialist parties.
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Purple States
A purple state refers to a swing state where both Democratic and Republican candidates receive strong support without an overwhelming majority of support for either party. Purple states are also often referred to as battleground states.
 
The demographic and political applications of the terms have led to a temptation to presume this arbitrary classification is a clear-cut and fundamental cultural division. Given the general nature and common perception of the two parties, “red state” implies a conservative region or a more conservative type of American, and “blue state” implies a liberal region or a more liberal type of American. But the distinction between the two groups of states is hardly so simplistic. The analysis that suggests political, cultural, and demographic differences between the states is more accurate when applied to smaller geographical areas.
 
Traditionally, the practice of designating a U.S. state as “red” or “blue” is based on the winner-take-all system employed for presidential elections by 48 of the 50 U.S. states and the District of Columbia. (Electoral law in Maine and Nebraska makes it possible for those states to split their electoral votes; this actually happened for the first time in 2008, when Nebraska’s 2nd congressional district assigned its elector to Barack Obama.)
 
Despite the prevalent winner-take-all practice, the minority always gets a sizeable vote. Because of this, a third term has emerged, referring to these closely-divided states as purple states. Furthermore, it could be argued that all states are “purple” to varying degrees and that the “red vs. blue” division is far from an accurate description of US culture.
 
All states were consistent in voting for George W. Bush or his opponent in the 2000 and 2004 presidential elections except for three: New Mexico (Gore in ‘00 and Bush in ‘04), Iowa (Gore in ‘00 and Bush in ‘04) and New Hampshire (Bush in ‘00 and Kerry in ‘04). The 2004 election showed two of these three states to be true to the presidential preferences of their respective regions, creating a greater regional separation; thus, an argument that the country is more divided from the 2000 election. All three of those states were very close in both elections. In 2008 Obama carried Iowa and New Hampshire by more than 9 points, and New Mexico by double digits.
   
1 February 2004, Newsday (Long Island, NY), “Dems Face Off in Bellwether State: Missouri,” pg. A28:
In a nation divided between Republican red and Democratic blue states, Missouri is a purple state - a blend of the two colors.
   
8 February 2004, Sacramento (CA) Bee, “Are Latino voters about to make Arizona a Democratic state?,” pg. E6:   
“There are blue and there are red states, right? Well, we’re a purple state,” said Barry Dill, a Phoenix political consultant and lobbyist…
     
Government Executive
The Nader Effect
By Charlie Cook
National Journal
March 16, 2004
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In the nation’s “reddest” states—ones that Bush carried by at least 5 points—Bush leads in a two-way trial heat among likely voters by 3 points, 50 percent to 47 percent. Kerry leads by 13 points in the “bluest” states, the ones where Al Gore won by 5 points or more. In the “purple” states—where the 2000 contest was closest—Kerry is ahead by 16 points, 55 percent to 39 percent. For Kerry, the problem is that the Electoral College magnifies the clout of states with small populations. And except for Delaware and Hawaii, they tend to vote Republican. 
   
Government Executive
Political Balance
By Charlie Cook
National Journal
April 20, 2004
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Anyone who spent time in March in the 18 “purple” states—the ones considered up for grabs in this presidential election—endured a Dresden-like bombardment of anti-John Kerry campaign ads by the Bush campaign.
     
New York (NY) Times
‘Fahrenheit’ Ads Use the Fuss the Film Is Causing
By FELICIA R. LEE
Published: June 23, 2004
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Tom Ortenberg, president of Lions Gate Films, the independent distributor for ‘‘Fahrenheit,’’ said that the film was being marketed ‘‘in a totally nonpartisan manner,’’ despite efforts by many to make ticket sales a referendum on the political mood.
 
’‘We’re in all 50 states,’’ Mr. Ortenberg said. ‘‘We’re going in red states and blue states and purple states.’’
 
New York (NY) Times
THE REPUBLICANS: THE CONVENTION IN NEW YORK—THE CONVENTIONEERS; Swing-State Delegates Confident in Bush and Don’t Much Like Kerry
By MICHAEL COOPER; Thomas Crampton, Mark Glassman and Marc Santora contributed reporting for this article.
Published: August 31, 2004
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But she noted that there was a reason some commentators call Pennsylvania—a state that is neither red nor blue—a purple state.