Is this Barack Obama's moment?
Updated on 04 November 2008
Turnout in the US elections could be the highest for a century. But are Americans voting for Barack Obama or John McCain?
After one of the longest ever presidential campaigns, and the most expensive, today a record turnout is expected as up to 140 million Americans cast their votes.
But there is no let-up for the candidates just yet. For John McCain it was a last-minute dash through Colorado and New Mexico. His running mate Sarah Palin will join him in Arizona to watch the results.
Barack Obama voted early in his home town of Chicago. More than one million people are expected at a massive rally in the city late tonight.
Whatever the outcome at the polls, this is truly a historic day. Our Washington correspondent Sarah Smith reports.
Electoral college explained
Channel 4 News explains the ins and outs of voting for an American president.
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Interview: Richard Johnston
Inevitably, perhaps, there have already been some problems at the polls. There have been reports of ballot papers running out, confusion over new voting systems, and calls for polling stations to stay open late to cope with the sheer influx of voters.
But can the turnout so far tell us anything about which way the result might go?
Jon Snow speaks with Richard Johnston, who is professor of political science and a polling specialist at Pennsylvania University.
A Pennsylvania story?
With few other options, John McCain has staked his entire campaign here in Pennsylvania, with a mighty 21 electoral college votes.
This strongly blue-collar state has clobbered the Republicans in recent times. But after several appearances, and with his low-tax message playing well, John McCain is hoping a major upset here could turn his fortunes around.
In Philadelphia the polls opened at seven o'clock. The queues - or lines, as they say here - quickly built up.
It seems this is an election everyone wants to be part of. Millions of young people have applied to vote for the first time - one internet video encouraging people to turn out has winged its way to more than 10 million.
And this being the United States, Starbucks and Krispy Kreme are involved in the vote too.
Jon Snow has been out on the streets of this historic city, where John McCain has gambled all to try and snatch the state of Pennsylvania off Barack Obama, to witness a mixture of American organisation and enthusiasm.
Interview: Michael Nutter
And joining Jon Snow is the mayor of Philadelphia, Michael Nutter.
