The result in Florida nudged George W Bush over the finishing line in 2000, but not before a hugely complicated process involving lost votes, missing voters, recounts, court appeals and a Supreme Court decision.
State election officials will be hoping the process will be less contentious this time, although the result could be just as close.
This is becoming a pattern - Florida was also a 50:50 state for the 1992 and 1996 presidential contests. The first President Bush won in 1992 and Bill Clinton in 1996. Healthcare is always an important issue in a state with a substantial elderly population (2.8 million in 2000 - at 17.6% the highest percentage of any state).
Still, Florida today is more than the sunny retirement home that it used to be. While the elderly population continues to grow, so does its juvenile population. Florida can also be violent, chaotic and disorderly. It is a sprawling state with no defined focus.
Population: 15,982,378 (ranked 4 among states)
Governor: Jeb Bush (R)
Electoral College votes: 27
This is just one of many changes the state has undergone. It used to be an isolated, malaria-ridden swamp but is now a tourist capital. It used to be the least-populated state in the South, but now with 16 million people it is the fourth largest in the nation. It is expected to overtake New York and become the third largest by 2025.
Part of that growth is due to Miami, the state's economic and commercial capital, with strong links to Latin America (like many American states, its political capital is relatively unknown - Tallahassee). International trade is important to the state, with the service sector and tourism increasingly important - the latter generated $41bn in 1997.
House of Representatives:
7 Democrat, 18 Republican
Senate: 2 Democrat
In part as a result of this, in part causing this, Florida has seen a huge influx of Latin Americans seeking new opportunities. These new immigrants have joined the large Cuban community based in southern Florida.
Some long-term residents are worried that the Hispanic population has such a clear identity that it can look like a state within a state.
2000: Bush 49%, Gore 49%
1996: Clinton 48%, Dole 42%
1992: Bush 41%, Clinton 39%, Perot 20%
In recent years its southern location and affluence have helped it "trend" Republican at a state level. Today, most state officials are Republican and in 2002 Jeb Bush, the second son of former President George Bush, was re-elected governor.
The Republicans will be keen to pick up the Senate seat of retiring Democrat Bob Graham.