I think part of the problem is that voting populace don't fully understand the cause-and-effect of the government being as big as it is. They're personally not seeing direct effects on their lives, or they think "It's the other party's fault!!!".
I agree, most don't comprehend it. Heck there is a bill being worked up right now which will allow the FBI to completely ignore the 4th amendment and access your Internet browsing history without a warrant and without your knowledge at all. Most people probably don't know that, and many probably won't care anyway because "I'm not doing anything wrong." All of this under the guise of making it easier to catch terrorists or potential terrorists.