That is a just an ad hominem attack - of course fiscal conservatives (and classical economists, austrian economists, monetarists) aren't ignorant of the Keynesian multiplier, they just don't agree that it is true. The best research I have seen shows that the multiplier is closer to .6, so this kind of government spending is useful to prevent starvation, but not at all good for the economy. Here is a good summary of the research that was published by the authors in the wall street journal:

http://online.wsj.com/article/SB1000142405274870447150457444...