How the Swing States Work

States and Their Leanings

This winner-take-all system is what led to the creation of swing states, as well as states in which votes just aren't particularly important. How can you tell the two apart?

There are nine states -- Alaska, Utah, Wyoming, Kansas, Idaho, North Dakota, South Dakota, Nebraska, Oklahoma, Indiana and Virginia -- that have voted for Republican candidates for the last 10 presidential elections. In fact, in almost all cases, the votes weren't even close. The Republicans enjoy a huge majority in eight of those states; in Virginia, Republicans won by just an 8 percent margin in 2004. In Wyoming, Utah and Idaho, Republicans had about a 40 percent majority in 2004. Montana, Colorado, Arizona, Mississippi, Alabama, North Carolina and South Carolina have only voted for the Democratic candidate once in the last 10 elections.

Democrats don't have an overwhelming hold on any states quite the way Republicans do. In fact, there are only five states that show a strong tendency to vote for Democratic candidates: Massachusetts, New York, Minnesota, Maryland and Hawaii. These states have tended to vote Democrat 70 percent to 90 percent of the time since 1964.

What does this mean to the average voter? If you live in Wyoming, for example, you can vote Democrat all you like, but the fact remains that the majority of the voters in that state will vote Republican, so the Republican candidate will get all the electoral votes.

Swing states (see map above) are ones in which recent presidential elections have been decided by a narrow margin -- in some cases, less than one percent. In 2000, New Mexico, Florida, Iowa, Oregon and Wisconsin had the closest margins, with the vote in each state decided by less than 1 percent. Florida's famous disputed vote came down to 537 votes, or 0.01 percent. With Florida worth 25 electoral votes at the time (it now has 27 electoral votes), those were 537 incredibly important votes. In 2004, Wisconsin, Iowa and New Mexico once again had the closest margins, with the vote in each state decided by less than 1 percent. New Hampshire, Nevada, Ohio and Pennsylvania were all very close, too -- the vote in each state was decided by less than 3 percent.

Sometimes states are considered swing states for reasons beyond close margins. For example, for the 2004 election West Virginia, Louisiana, Arkansas and North Carolina (because it is the home state of Senator John Edwards, who was Kerry's running mate in 2004) were also considered swing states by political analysts.

What's it looking like for the 2008 election? Washington Post political blogger Chris Cillizza lists Iowa, New Mexico, Nevada, Colorado, Ohio, Virginia, New Hampshire, Florida, Minnesota and Missouri as potential swing states in the 2008 election [source: Washington].

Of course, politicians have known about swing states for decades. Let's find out how it affects their campaign strategy.