It is no coincidence the US Republicans chose to hold their nominating convention in Florida, for the state could determine the fate of White House challenger Mitt Romney in November's election.

Home to 11 million registered voters, Florida is a key swing state and proved decisive in 2000 when Republican George W. Bush beat Democrat Al Gore after a recount contested all the way to the US Supreme Court.

"Florida is the key state for the election. It's the largest swing state," said Carol Weissert, a political scientist at Florida State University.

With a little over 10 weeks to go until election day, polls are split over whether President Barack Obama or Romney, a multi-millionaire businessman and former Massachusetts governor, holds the edge in the Sunshine State.

An Quinnipiac University/New York Times/CBS survey conducted last week put Obama ahead by three percentage points, but a Rasmussen Reports poll on August 15 had Romney up by two. Both forecasts were within the margin of error.

Florida has a diverse mix of voters, making the state a complex battleground.

Nearly 18 percent of the state's 19 million residents are above the age of 65, according to 2010 census figures. Senior citizens are usually reliable voters and have tended to tilt Republican.

More than three-quarters of Florida residents regard themselves as white, according to the census, although the state does have significant Hispanic and African American minorities.

For decades Florida's Hispanics were typically Cuban Americans that overwhelmingly voted Republican because of the party's perceived stronger support for the cause of overthrowing left-wing Cuban leader Fidel Castro.

But the latest generation has a more mixed voting record and a growing proportion of Florida's Hispanics are from Puerto Rico or of South American origin and more inclined to vote Democrat.

Obama won Florida by a slim majority in 2008 with a huge turnout of young people and Democrats. "Obama needs to do it again to win in 2012," said Weissert.

And while experts say the president has a reasonable chance of being re-elected even if he loses Florida, the state is seen as make-or-break for his Republican challenger.

"It is very difficult to see how Romney can win without carrying Florida," said Larry Sabato, a political science professor who is the director of the University of Virginia's Center for Politics.

"Florida is very critical for both parties. For Republicans, they cannot win without winning Florida," agreed Susan McManus, a professor in the University of South Florida's political science department in Tampa.

No surprise then that Romney has chosen to be anointed next week in the Florida gulf coast city of Tampa.

At the August 27 to 30 event, plenty of time has been allotted for Florida personalities, including popular former governor Jeb Bush, present Governor Rick Scott and telegenic state Attorney General Pam Bondi.

Florida Senator Marco Rubio, a youthful Cuban American and a rising star in the Republican party, has been given the exalted role of introducing Romney on the final night of the convention.

American presidential elections are decided not by the overall popular vote but by adding up so-called electoral college votes, which are awarded on a state-by-state basis.

With 29, Florida is the swing state that has the largest number of electoral college votes up for grabs. California (55) and Texas (38) have more but the first is solidly Democrat and the second firmly Republican.

McManus argued that with polls narrowing for Obama in other swing states such as North Carolina and Indiana, Florida was now becoming a must-win for both parties. Sabato, however, disagreed.

"More likely Ohio or Virginia will be the key state, but you can play this game endlessly in August," he said. "No one knows."