Maher isn't really part of the traditional media except for the fact that he's a political commentator, which anybody can be provided they have a platform from which to speak. As such, it's incredibly tendentious to dismiss Maher like that. It's almost like arguing, "D'Souza is a hack. Of course he would say hackish things." But that doesn't really address anything either person is saying.
Maher brings up good points. Unfortunately, he kind of lets D'Souza go when D'Souza attempts to absolve Bush of blame for the national debt. Most of the deficit is the product of things that occurred under Bush: the tax cuts, the two wars, and the financial crisis.