As an American, I've never had issues navigating government websites. That said, I'm also not part of the apparently huge portion of our population who can't read above 6th grade, which I suspect is more of the issue than anything said here thus far.
Well we can’t exactly hang those people out to dry after failing them in our educational system. I refuse to believe that many Americans are simply incapable of reading beyond that level. I believe it is a failure of our culture.
I would be careful not to confuse navigating a government built website with finding information and records from government related entities. Those two are not the same issue and shouldn’t be painted as such regardless of one’s reading or comprehension (IMHO)