According to the New York Times, the US government has committed $3.1 trillion as an insurer, $3.0 trillion as an investor, and $1.7 trillion as a lender.
However, the Times omits roughly $5 trillion in guarantees made by Fannie Mae and Freddie Mac that are now officially on the government balance sheet. The total of commiitted bailout funds (without any auto industry funding) is now at $12.8 Trillion.
US GDP is about $14 trillion per year; the budget deficit in recent years has been running in the half-trillion range. So that means that the total government spending is roughly 13.3 / 14 T = 95% of the entire US GDP!
The US government is betting that actual spending will be less – provided that that banks can repay some of these loan guarantees and preferred securities. But with dominos now falling across the US auto and other manufacturing sectors, and with the housing and construction sector in the toilet, it is not hard to imagine a second phase to the banking crisis that serioiusly impairs these repayments.