In United States presidential politics, a swing state (also, battleground state) is a state in which no candidate has overwhelming support, meaning that any of the major candidates have a reasonable chance of winning the state's electoral college votes. Such states are targets of both major political parties in presidential elections, since convincing winning these states is the best opportunity for a party to gain votes. Non-swing states are sometimes called safe states, because one candidate has strong enough support that they can safely assume they will win the state's votes. In these states, candidates often focus on swing voters, who could conceivably vote for either candidate.
Origin of swing states
In the presidential elections of the United States, the U.S. Electoral College system means that only the winner of a state receives any benefits from it (i.e. electoral votes). If a campaign wins a plurality of the popular vote in a state, the candidate receives all of that state's electoral votes; no benefit is gained from receiving additional votes above the margin necessary to win (this is true of 48 of the 50 states and the District of Columbia; the two exceptions, Maine and Nebraska, are explained below). This fact produces a very particular set of circumstances that explains the existence of swing states.
Since a national campaign is interested in electoral votes, rather than the national popular vote, it tends to ignore states that it believes it will win easily; since it will win these without significant campaigning, any effort put into them is essentially wasted. A similar logic dictates that the campaign avoid putting any effort into states that it knows it will lose. For instance, a Republican candidate (the more conservative of the two major parties) can easily expect to win Texas and several other Southern states, which historically have a very conservative culture and a more recent history of voting for Republican candidates. Similarly, the same candidate can expect to lose California and Massachusetts, traditionally liberal states, no matter how much campaigning is done in that state. The only states which the campaign would target to spend time, money, and energy in are those that could be won by either candidate. These are the swing states.
Only two states—Maine and Nebraska—violate this winner-take-all rule. Under their system, two electoral votes go to the person who wins a plurality in the state, and a candidate gets one additional electoral vote for each Congressional District in which they receive a plurality. Both of these states have relatively few electoral votes (for the 2004 election, Maine has 4 and Nebraska has 5; the minimum is 3) and are usually not considered swing states. Despite their different rules, neither has ever had a split electoral vote.
Separately, Colorado will be voting on an initiative this November which would allocate the state's electoral votes in proportion to the popular vote in the state. The initiative would take effect immediately, applying to the selection of electors in the same election.
Determining swing states
The actual procedures for deciding which states are swing states in any particular election varies across campaigns and across disciplines. Many political scientists use historical voting patterns: the more often a state has been won by candidates of one party in the past, the more likely it is to vote for that party in the future. Other factors that can help determine which states are swing states are:
- The state's results from the last presidential election
- The state's results from the last several presidential elections
- Opinion polls
- Any historical trends that the campaign believes might lead a state to vote for one party or another
- The state of origin of the candidate, and also that of the candidate for Vice President
Swing states tend to have a fairly equitable balance of city and country-dwellers; states that are highly urban or highly rural are less likely to be swing states.
Historical swing states
The swing states of Illinois and New York were key to the outcome of the 1888 election. The swing states of Illinois and Texas were key to the outcome of the 1960 election; however, today Illinois (D), New York (D) and Texas (R) are not considered swing states. Ohio has often been considered a swing state, having voted with the winner in every election since the 1950s except for 1960. The most reliable swing state of the last 100 years has been Missouri which has voted for the winner of every presidential election since 1904, save for its support of Adlai Stevenson in 1956.
2004 swing states
While the swing state of Florida received much press with regard to the outcome of the 2000 election, several other states had similarly close outcomes and could have changed the outcome of the election. The following is a list of the states with the lowest margins of victory, sorted by the margin percentages and color-coded for Bush or Gore:
- Colorado- 9% 145,518 votes
- Virginia- 8% 220,200 votes
- Louisiana- 8% 135,527 votes
- Arizona- 6% 96,311 votes
- West Virginia- 6% 40,978 votes
- Ohio- 5% 165,019 votes
- Arkansas- 5% 50,172 votes
- Tennessee- 4% 80,229 votes
- Nevada- 4% 21,597 votes
- Missouri- 3% 78,786 votes
- New Hampshire- 1% 7,211 votes
- Florida- .01% 537 votes
- New Mexico- .06% 366 votes
- Wisconsin- .22% 5,708 votes
- Iowa- .32% 4,144 votes
- Oregon- .44% 6,765 votes
- Minnesota- 2% 58,607 votes
- Maine- 5% 33,335 votes
- Washington- 5% 138,788 votes
- Pennsylvania- 5% 204,840 votes
- Michigan- 5% 217,279 votes
In a recent article, the Washington Post defined swing states as those that were decided by less than three percentage points in the 2000 presidential election. Using those criteria, the swing states for 2004 are Oregon, New Mexico, Iowa, Minnesota, Wisconsin, New Hampshire, and Florida. The Los Angeles Times, in a pre-Super Tuesday evaluation of the Democratic slate, also named Ohio and Missouri as other critical swing states. Bloomberg adds West Virginia, Pennsylvania, Iowa, Michigan and Nevada and says the two major parties believe 18 states are in play in 2004. Molly Ivins, in an April 3, 2004 column, also lists Louisiana. In an April 28 Washington Post feature on the red state-blue state split in America, potential 2004 swing states listed as: Florida, Iowa, Minnesota, Missouri, Nevada, New Hampshire, New Mexico, Ohio, Oregon, Pennsylvania, Tennessee and Wisconsin. In John Kerry's presidential campaign, many consider Virginia a swing state.
- Arizona: 10 Electoral votes
- Arkansas: 6 Electoral votes
- Delaware: 3 Electoral votes
- Florida: 27 Electoral votes
- Iowa: 7 Electoral votes
- Louisiana: 9 Electoral votes
- Maine: 4 Electoral votes
- Michigan: 17 Electoral votes
- Minnesota: 10 Electoral votes
- Missouri: 11 Electoral votes
- Nevada: 5 Electoral votes
- New Hampshire: 4 Electoral votes
- New Mexico: 5 Electoral votes
- Ohio: 20 Electoral votes
- Oregon: 7 Electoral votes
- Pennsylvania: 21 Electoral votes
- Washington: 11 Electoral votes
- West Virginia: 5 Electoral votes
- Wisconsin: 10 Electoral votes
A survey conducted by a firm for the Bush campaign also gave a figure of 19 states, but with slightly different results. It cited these states as "the 19 battleground states in which the Bush and Kerry campaigns have focused their paid media efforts to this point". The states were:
- New Hampshire
- New Mexico
- West Virginia
Some observers have labeled Ohio as the most important battleground state. The Gore campaign in 2000 gave up on Ohio with weeks to go before the election, but some statistics seem to indicate that Gore was gaining ground there and might have won the state had he persevered. With Ohio, Gore would not have needed Florida to win. The state remains in play this year with polls seeming to show Bush and Kerry running neck-and-neck. Ohio has not gone to the losing candidate since 1960, when Richard Nixon won Ohio but lost the election to John F. Kennedy.
Traditionally, labor unions have had a strong grassroots network in the state. However, since 1970, Ohio's manufacturing base has taken one hit after another, with more big blows coming during the George W. Bush administration. A weakened union organization is accompanied by an Ohio Democratic Party that is in shambles. While the Kerry campaign must build its Ohio campaign from the ground up, the Ohio Republicans have spent months building a grassroots campaign modeled on multi-level marketing schemes such as Amway. 
Other terms for swing state
- Battleground state
- Purple state, so named because purple is the combination of the colors red and blue, which (since 2000) are used to represent Republican and Democratic-majority states, respectively.
- Better World Links on Battleground States & Swing State Polls
- Coverage of battleground states in 2000 election from CNN
- Guide to the 2004 swing states from Slate
- Battleground states from Democracy in Action site hosted by George Washington University
- The Swing States from Intervention Magazine
- Swing State Project, a law student's weblog
- The Bush campaign memo detailing its look at the swing states (PDF file)