Not trying to be insulting here, but the kinds of people with knowledge of and access to the internet, plus the abundance of time to post frequently, are generally going to NOT be right leaning people. First off, it takes a certain mind set to want to interact with a wide variety of people with major social differences to yourself, which is something your average conservative is not known for doing. Second, right leaning people tend to not examine sources of information outside their own spheres of influence, which a good chuck of centrists and lefties do. I listen to Hannity and some Fox News every once in a while in an attempt to get some insight into what the really right leaning people I know are thinking, even though it usually sounds like a slightly toned down version of a General Anthony post. How many right leaners do you know that actually scope out even the more reasonable leftish shows in the same way (Maddow, Chris Hays, ect) to get some insight into the left? Also, outside certain parts of the financial and energy industries, most right leaning people tend to be blue collar types without the abundance of time to post random though, while your average liberal net savy guy is some IT nerd working at a desk posting between progress meters filling up. Finally, the right has vilified education and critical thinking to the point where sitting in your echo chamber and avoiding any display of intellect is actually celebrated. This leads to shit like them not even knowing where Bengazi is on a map while bitching about fuckin Obama or "keep your government hands off of my medicare", among hundreds of other examples. They use the bible as a means of making policy decisions involving science. Thus, the (non-sanitized for right wing thinking sections) of the internet tend to be center or left leaning, because conceptually it is a better fit. Generally when you see a larger right wing presence in a part of the internet, its either by design (conservapedia, ect) or simply racist assholes being given an anonymous platform (General Klansman, ect).
Not to say the left does not have its problems, but this is why most relatively unmoderated communities tend to end up being left center. Honestly, if this board were as dominated by liberals as you guys think, the ban hammer would have come down on several problem people for the racist shit along, I think.