This one was easy - even posted a day late.
George W. Bush
I mean, come on. A seven hundred BILLION dollar bailout?
If you want to spend more than the Iraq war has cost (on paper, at least) to date, earmark it for infrastructure development. The US hasn't seen major infrastructure spending since the 1950s, and never has it needed it more than today. But come on! You're nearly twelve trillion dollars in debt, and your solution to the credit crisis is to spend more? Where are you going to get it? I can't think of any country who would extend you that much in additional credit. Which leaves you one option: print money.
So, you put an additional seven hundred (what was that? Oh yes) billion dollars into circulation. What, pray, would this do to your dollar's value? Oh, right. Ask the Germans, right before World War II, say. They might be able to tell you.
Now, on top of all this, there are a couple trillion dollars of imaginary money that's sitting and souring in the financial markets. Seven hundred billion dollars, as mind-boggling a sum as it is, won't actually solve the problem unless the government takes a hand in legislating the economy, rather than the hands-off laissez-faire technique which has been the hallmark of the "free market" politicians since the Nixon era. If they don't, all it'll do is keep the eggs in the air for a few more months.
Which may be the point.
If he can keep it going a few more months, Bush can dump the economy on the next person to take office... in legal terms, the "chump."
Therefore, I give you the Asshat of the Day. George W. Bush.