Campaign finances.

Here's a detailed breakdown of fundraising and spending between the two campaigns. Some interesting highlights:
By far the biggest lead between the two campaigns is the use of small donors by Obama, which gave him $150 million more than small donors gave to McCain. Also, lawyers and teachers gave far more money to Obama than to McCain, the only profession that gave McCain more were real estate agents.

Obama needs to bring in more than $85 million in the next two months to make his decision to forgo public financing worth the extra time he has to spend at fundraisers, but it looks like he'll beat that sum by quite a bit. Money obviously doesn't buy votes, and I hope that, as the campaign turns more negative, Obama's ads will be truthful and focus on legitimate policy and character issues, instead of the recent stuff that McCain has been posting.

Though Obama did stretch the truth by claiming that McCain wanted to cut school spending (he actually voted to limit its growth), I hope that that is as bad as he gets... i.e. his character is a strong point and weakening it through those types of distortions makes me cringe. However, it is necessary for Obama to go more negative and tell all of Palin's story: her ideology, politics, and methods are so far out of the mainstream that she should be a burden for McCain as time goes on.