I am a student of economics (political economy to be exact, which teaches some more far out stuff than the mainstream).
I will say this for the Keynes argument.
Nothing America has ever done has ever been close to the prescriptions of Keynesian economists. The New Deal was a paltry stimulus pulled back too early to fill the largest demand deficiency in history, only WW2 (the most massive stimulus in history) pulled it out and even then you tend to waste a lot in a war, but hey at least those boys came home to jobs and veterans assistance.
Obama's Stimulus was somewhere in the range of less than half of what was necessary to fill the gap caused by the GFC.
And Bush's bank bailouts were misguided as Keynesian prescriptions (as adopted in Australia during the GFC) would have been to support the consumer instead to save the bank. We accomplished this by guaranteeing consumer bank deposits (to a generous limit) against the governments credit rating which prevented a run on the banks and restored immediate confidence to the banks.
Please note that Australia is one of the few countries in the Western world doing well right now as the EU, Canada, the UK and USA flounder. Even if some of our stimulus spending was misplaced or had cost blowouts (such as the school building upgrade program) it was sufficient (better too much than too little) to keep Aus unemployment down and growth up.
Keynesian economics works. But I'm not sure the USA will ever accept it politically. It's not perfect, but it's been right the most times out of the economic theories that make predictions.
Oh and to whoever said that Keynes was dominant through the 20th and 21st centuries, you have never read Keynes. Only the most irrefutable parts of his theories were adopted as a bastardised version under the heading "Macroeconomics" and that only lasted from the 1940's up until the late 1960's when Monetarism, then Neo-liberalism became dominant.
