There has been a flurry of news stories on this final weekend of the epic 2008 election, and everyone – inside and outside of the campaigns – is trying to figure out what impact they might have.

Such things are hard to assess except in hindsight. So it’s worth looking back four years ago, to where we stood so close to the Bush-Kerry contest.

On the Saturday before the election, Osama bin Laden released a new video in which he claimed that American security lay not in Kerry or Bush’s hands, but in the hands of voters to end the war on terror. Kerry’s aides later blamed the video for their ultimate defeat.

This time around, the stories that have emerged include the illegal immigrant status of Obama’s half-aunt, and Dick Cheney’s late endorsement of John McCain. Neither has the impact of the world’s most wanted mass murderer. Neither speaks to any voters beyond the base of supporters who already support McCain and Obama.

And inside the Obama campaign at least, there’s no sign that the numbers are moving anywhere.

The Gallup polls on November 1, 2004, showed an even split in the battleground states and a national race that leaned toward President Bush by just two points. In Wisconsin Bush led by 8; in Minnesota Kerry led by the same margin. In Iowa Bush was up 2, and in Pennsylvania he was up by4. In Florida Kerry was up by 3, and in Ohio he was up by 4.

Of those six states, the only two correct results were Kerry winning Minnesota and Bush winning Iowa. The lesson: in the tightest battleground races, the margin of error is a meaningful measure. This time around, those states include Ohio, Missouri, Indiana, Florida and North Carolina.

This weekend, Gallup’s tracking polls have remained remarkably consistent. Gallup has three sets of numbers – registered voters, likely voters based on an expanded turnout, and likely voters based on traditional turnout. On Saturday, Gallup showed Obama up by 11 points among registered voters, and 10 points in both models of likely voters.

Perhaps the most remarkable Gallup number of all: 27 percent of their sample has already voted. At the current rate, by Election Day that figure will be somewhere around 40 per cent. That means last-minute stories have far less impact in this cycle than they did four years ago.

John McCain is in Virginia this morning, kicking off the final weekend of the campaign in a red state that is threatening to turn blue. It’s worth noting that he’s in what his campaign has referred to as “real Virginia”—Newport News—but we’ll be flying from here to Springfield, a suburb of Washington, D.C., for his final rally in the state before Election Day. From here, we will spend the rest of the day in Pennsylvania before heading to New York City, where McCain will appear on Saturday Night Live tonight. Details are still being worked out, but, according to a senior McCain adviser, the candidate will almost surely appear in a skit with Tina Fey as Sarah Palin.

Tomorrow, McCain spends part of the day in Pennsylvania before heading to New Hampshire, where he’ll hold his final town hall of the campaign in Peterborough, a place that McCain regards as something of a lucky charm. He held his first town hall meeting there during his 2000 campaign and wound up there on the eve of his comeback primary victory earlier this year. It’s “where our campaign has been rescued and resurrected many times before,” Rick Davis, McCain’s campaign manager, told reporters yesterday. Yet privately, McCain and his aides are unsure if it will be as lucky this time around. Down by 13 points in the state according to poll released yesterday, McCain and his aides view his stop there as more nostalgic than game changing. Indeed, a senior McCain aide says the candidate and his advisers have gone back and forth in recent days about whether the stop was time well spent in the final hours of the campaign. Also of great debate: Whether it was a good idea for McCain to take questions from voters, that could risk sending the candidate off message, or simply hold a rally. His aides were split, but in the end, McCain himself made the call: He would do a town hall.