Keynesianism is the false belief that "math, "evidence", and "facts" are a good way to run an economic system. It sometime requires countries to carry a deficit in order to save their economy, when everyone already knows the only good reason to carry a deficit is to build up a military in order to prepare to fight an enemy that ceased to exist 20 years ago, or to fight a war that is totally justified because a guy we don't like might have some weapons (and oil) And if turns out he doesn't have them then is is because he is a bad person (with oil). Or because people are paying nearly %15 percent of the tens of millions of dollars they make every year into federal taxes and they need relief, no matter the cost to the economy. But to try and prevent a Great Depression with Keynesianism is just stupid. The idea that you can impove an economy by stimulating is like believing that you can run an internal combustion engine with gasoline. Obviously taxes need to be cut further for the very wealthy so that they can hide their money and make sure that common people don't try to use it to improve the stupid country, because that would be unpatriotic.
It should also be noted that; if a Republican is president, deficits don't matter.