$427 billion is predicted for the current fiscal year.
Democrats will blame Bush and the Iraq war exclusively. At $105 billion for the current year, the Iraq war is certainly contributing the the deficit, but take away the $105 billion and it's still a pretty huge $322 billion.
I blame the culture of big government and big spending. Bush's domestic policy is about new and unnecessary programs and not eliminating existing programs.
Clinton was lucky that he was president during the time of the stock market bubble, when capital gains and corporate incomes were at an unsustainable cyclical peak. Bush doesn't have such luck, so he must reduce the budget deficit through spending reduction.