It is partly the novelty of the first woman and black candidates to have serious prospects of entering the White House. It is partly the widespread relief that the Bush-Cheney era is drawing to a close. It is partly the thrill of the horse race and the widespread view that this is likely to be a cliff-hanger.
It is partly the looming threat of a global economic slowdown turning into a global recession as oil and food prices squeeze consumers and threaten inflation around the world. It is also the rise of China and the resurgence of a militant and aggressive Russia showing how far and fast the world is changing.
And to a very great extent it is the Internet and the media age that brings each up and down of the campaign into the world's living rooms and cafes and conversation.
From radio talk shows in Moscow to Internet chat rooms in Shanghai, from the online forums on the BBC Web site to al-Jazeera in English and Arabic, almost anybody anywhere can now keep up with the latest polls and gaffes and plot twist in what has become the greatest show on Earth. From the cafes of Paris to the bazaars of Istanbul and the nightclubs of Nairobi, they can tell you about the importance of Ohio and Florida as swing states.
We know that almost 40 million Americans watched Sen. Barack Obama's speech accepting his party's nomination for the presidency. Probably 10 times that number around the world watched or heard at least some of it, since understandably a large proportion of the 6.5 billion humans who share this planet feel that in some profound way Obama is their candidate, too. In Kenya where Obama has family roots and Indonesia where he studied, he carries the kind of resonance that Jack Kennedy and Ronald Reagan touched in their ancestral Ireland.
Europeans and NATO allies and Canadians and some others have long felt a touch aggrieved that they did not have a vote in the election of the person who was, after all, also to become their leader. The head of the free world held the fates of a vast number of people in his hands. These days it seems that just about everybody on the planet with access to a TV or radio feels they have a personal stake in the outcome of this race.
And what a race it already is! Obama, D-Ill., came out of the starting blocks at the end of a very successful convention week with his party united and the Gallup poll giving him an 8-point lead over John McCain.
But then McCain trumped that with the daring and unexpected choice of Alaska's first-term governor, Sarah Palin, as his running mate, and once again we had the full mix of race and gender among the candidates. The two tickets could have been dreamed up by central casting: a young black man, a young white woman and two veteran white senators, all contending for the most powerful job in the world.
The Zogby poll, the first taken after the Palin announcement, gave McCain-Palin a 2-point lead over Obama-Biden. That was significant because Zogby had run an interactive poll on a large sample of more than 2,000 people, all of them likely voters rather than just registered voters.
Moreover, an interactive poll make it easy to go back with secondary and follow-up questions, so Zogby was able to record that 22 percent of those voters who supported Hillary Clinton in their primary elections or caucus earlier this year are now supporting McCain. Expressed on a national scale, that could mean 3.5 million voters who would have gone Democratic if Hillary had been the nominee may now switch. That level of resentment is unlikely to last, but it's still a sobering number for Obama.
Even worse was the Wal-Mart vote. McCain gets 62 percent support among those who shop at the discount giant regularly, while Obama gets only 24 percent. That's a frightening figure, suggesting that Obama is having real trouble winning blue-collar support among whites. Remember that in 2004 one of the best polling guides to Bush's defeat of John Kerry came from the Wal-Mart shoppers.
That same Zogby poll brought in the subplot of the impact the other candidates might have. It is close to being an item of faith among Democrats that Ralph Nader's quixotic campaign in the 2000 election took votes away from Al Gore that might otherwise have defeated Bush. Now Nader is running again, and that same Zogby poll suggested that Nader could get 2 percent of the total vote and 4 percent of the independent vote -- enough to swing a close race.
The real surprise, however, was that McCain seems far more at risk from the minor candidates than Obama. The same poll suggests that the Libertarian candidate, Bob Barr, could get 5 percent of the total vote and 11 percent of the independents. In such a four-way race with Nader and Barr both competing for voters, Zogby's figures put Obama just a hair ahead by a margin of 44 percent to 43 percent.
Amid all this nail-biting, Hurricane Gustav suddenly tore across the Caribbean to force the evacuation of New Orleans and squeeze the polling data -- and possibly the Republican convention -- off the front pages. It was a reminder that the great disaster of President Bush's second term was Hurricane Katrina and the pitiful response of U.S. authorities to the agony of that same city. Everything these days is political.
Can this level of intensity be maintained? Pollster John Zogby suspects that it might, saying over the weekend, "This contest is likely to be very close until the weekend before the election -- then the dam may break and support may flood one way or the other."