Most polls show the two candidates in a virtual dead-heat across the nation, while some polls give Bush a slight edge. Amid the political battle, early voting has already begun in several states, including Florida.

The key battleground state of Florida remains in the spotlight. A mere 537 votes pushed this crucial state into the Bush column in the controversial 2,000 election, giving the Republicans a razor-thin margin over Democrat challenger Al Gore.

As early voting began in the Sunshine State, both President Bush and Democrat challenger John Kerry took their campaigns there. Although no weapons of mass destruction have been found in Iraq, President Bush underscored why he thinks America will be a safer place under his leadership.

Bush said: "In an era of weapons of mass destruction, waiting for threats to arrive on our doorsteps is to invite disaster. Tyrants and terrorists will not give up polite notice before they attack our country. As long as I'm commander in chief, I will confront dangers abroad as we don't have to face them here at home."

But Senator John Kerry challenged Bush's premise.

Kerry said: "Mr. President, your management or mismanagement of this war, your diversion from al-Qaeda and from Osama bin Laden, your shift of the troops to Iraq when there was nothing to do with al-Qaeda, nothing to do with 9-11, has made America less safe, not more secure."

Whichever candidate wins more popular votes in Florida, wins all of the state's 27 electoral votes. A total of 270 electoral votes are needed to win the presidency.