What do we know and what do we not know?
The second question is easier. We obviously do not know what is going to happen over the next 55 days until the election. Little has been predictable so far about this election, so why should it start being predictable now?
We do know that both sides have picked presidential nominees and running mates, held conventions and gotten bounces.
In Gallup's daily tracking poll, Sen. , D-Ill., pulled his three-day moving average out as far as 50 percent -- the surveys run around 2,750 registered voters with a 1-point error margin -- all prior to the beginning of the GOP convention Sept. 1.
In the Gallup tracking conducted through Saturday night, Sen. , R-Ariz., clocked in with 48 percent to Obama's 45 percent. In the most recent wave, conducted through Sunday night, McCain came in at 49 percent to Obama's 44 percent.
In a separate poll Gallup conducted for USA Today those same three nights, McCain had 50 percent and Obama 46 percent among 959 registered voters. That tally had a 3-point error margin. When the USA Today poll looked at a subsample of 823 likely voters, McCain had 54 percent and Obama 44 percent, with a 4-point error margin.
This Gallup/USA Today poll also showed near-parity in party identification after months of showing a Democratic edge, suggesting either a massive shift in party identification, which is pretty unlikely, or a poll that is too heavily weighted toward Republicans.
The McCain margin in this poll might well be inflated a bit and traditional models tend to weight heavily older voters in an election that seems likely to feature many more young people than normal.
But, there is little question that McCain got his bounce just as Obama did after the Democratic convention. Polling later this week and next week should give a truer reading after the second convention's bounce has had a chance to settle down. Indeed, a CNN poll released Monday showed the Obama and McCain at 48 percent each. The CNN poll of 1,022 registered voters was conducted Friday, Saturday and Sunday and has a 3-point error margin.
Basically, the fundamentals argue for one outcome, but there is something else pulling in the opposite direction.
History argues that parties rarely win three times in a row; just once in five chances since the end of World War II. Presidential elections are usually a referendum on the party holding the White House.
With an incumbent president holding a job approval rating of about 30 percent, a war that a majority of the public believes was a mistake, an economy teetering on the brink of a recession, unemployment at a five-year high and mortgage foreclosures and delinquencies increasing at an alarming rate, this is certainly an inauspicious time for a party to be seeking a third term in the White House.
Exacerbating things for the GOP, Obama will have a significant advantage in terms of money and organization, and McCain's campaign field operation is significantly less formidable than both President Bush's four years ago and Obama's today, in every single state.
Finally, recent polls show voters preferring a Democrat winning the White House over a Republican by anywhere between 7 and 10 percentage points.
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Sarah Palin
All of this suggests a high probability of Democrats winning the White House, but there is something else. Obama seems to hit a resistance point, a ceiling, around 48 or 49 percent, only once grazing 50 percent in the Gallup tracking, performing well with enough groups to get up to the verge of a majority but not yet able to go beyond.
Whether one focuses on white voters over 50 or over 65 years of age, or white working class or non-college-educated whites over 50, Obama is underperforming pretty consistently, though his strength among black and younger college-educated white voters partially offsets the problem.
Democratic hopes that his convention acceptance speech, in an event worthy of Michael Deaver, would close the sale with some of these voters appears to have been premature. At the same time, McCain's choice of Alaska Gov. Sarah Palin has provided the Republican ticket with intensity it lacked and solidified the GOP base in a way that McCain, a perceived maverick, could not do on his own.
Some might debate strongly whether she is qualified to be vice president, but there is little doubt that so far she has proven to be a real asset to the ticket. Whether that remains the case is for God and the opposition researchers to decide, but so far, so good for the GOP.
In short, while the Senate looks most likely to end up with GOP losses of at least four, but most likely five to seven seats, and most likely between 12 and 17 seats in the House, this presidential race is very much up in the air. The fundamentals argue one thing, but there is a resistance that prevents it from being a done deal and a running mate that seems to have slowed down Democratic momentum.
This being the case, so many things become important. International or economic events that can pull the spotlight toward or away from one candidate's strong suit, debates, game-changing advertisements or arguments, resources and missteps all become potentially critical elements.