Eric Zorn gives eight reasons why Obama will win. None of them is the most obvious.
BREAKING! MUST CREDIT CHICAGOLAND!!!: PEOPLE LIKE MONEY AND WANT MORE OF IT
I spent a while yesterday reading articles and playing with tax calculators, and based on my very rough estimates, I would get about a $60 tax break under McCain's proposed tax plan. Under Obama's proposed tax plan, I would get about a $600 tax break.
I used this to get a generic estimate of what I would pay under the current tax structure given a standard COL raise [ed note: knock on wood! cross your fingers for me still having a job by inauguration!]. I used the Obama-Biden Tax Calculator to see what socialist redistribution would do for me.
OK, this part is significant enough that it deserves its own paragraph. Instead of a tax calculator, John McCain has a section of his site which depicts several scenarios in which a married white couple in a pastoral setting with two children would get tax breaks. One of the couples, in fairness, may be intended to be somewhat swarthy. Besides the fact that the presentation is obviously TOTAL DESIGN AND CULTURAL FAIL I am neither married nor have children and so that page is about as relevant as the untranslated Dead Sea Scrolls.
So I used the Election Taxes site and checked it against some news articles and it seemed to square: People like me, which is to say people who are far from wealthy, will get money get money under President Obama, and we can go out and buy drugs and see godless Hollywood entertainments the way Marx prophesied.
If you don't believe me or think that I may be in a small, culturally if not financially elite demographic, Viveka Welly at chartjunk did a clever, Edwart Tufte-esque redrawing of a Washington Post graphic that charts both the candidates' tax plans and their relationship to income distribution. It's really a great work of quantitative information design, but I've modified it slightly to make it a bit clearer in its implication, drawing on the work of some of our generation's finest economic theorists.
As you can see, the vast, vast majority of Americans will get a considerably larger tax break under Obama's dramatically progressive tax plan. Whether or not that makes fiscal sense is obviously a hot topic, but I am not trying to argue any economic theory more complicated than Occam's Razor. If you are voting for Obama, and a McCain supporter asks you why, and you don't really want to talk about it, just say you are voting your pocketbook. They won't think you're right, but generally the logic will make sense to them.
Update: This post by bonddad has a dramatic graphic about government spending and consumer spending vis a vis GDP that's extremely relevant to the discussion above.