Krgthulu's right on the economics, but the politics of Fed-financed spending versus Fed buying up Treasury bonds is that one adds to Teh Deficit and one does not. One adds to the scary big number which gives ammunition to the state destroying people who don't actually care about the deficit and one doesn't.
And, frankly, the shame of the last several years is that we've had an opportunity to have a free lunch and we turned it down. Telling the Fed to print some money and hand it over to the Treasury or drop it from helicopters makes this reality clear.
