There's a candidate on either side getting downplayed systematically by the American media - Edwards and Paul. Each is consistently represented across the mainstream media as winning less than he wins, having less supporters than he has, etc. In each case, the main reason the media blocks him, of course, is because people with money don't want to broadcast his views, and in the United States, people with money control the systems for broadcasting political views. (Even YouTube; the reason YouTube makes available a much wider variety of political views than most American systems for making political views available is because YouTube makes Google money.) It sucks that the media does this, but it's awesome that libertarians and progressives are finally becoming part of the mainstream political debate in the US.
But as much as that cheers me up, and as much as I want to support his struggle against The Man, with Ron Paul at least there's an additional reason the media shuts him down: a history of controversial, unpleasant remarks which appear to indicate bigotry pretty conclusively. The people who own and operate the media are isolated from those kind of sentiments, whereas many other people in the US have to deal with them regularly. Nobody in the media class wants to be reminded about the fact that there are still people all over the place supporting those views also. It's not just censorship; it's also distaste.
I'm not an expert on Paul, but if you're thinking about his campaign, that's one thing to keep in mind.
Update: Stolen from Ara T. Howard: