The First Amendment and freedom of speech applies to actions taken by the government only. There is nothing saying that a private entity, which obviously includes Free Republic, can't limit discussion on a forum it provides. To put it differently, Fox News doesn't have to let Bernie Sanders rant on about the evils of capitalism if it doesn't want to.
The owner/host/HMFIC of FR is Jim Robinson, who has every right to set any rules he chooses, or to "censor" opinions he believes do not support conservatism. And many a post has been "zotted" by the moderators if they believe it is pushing a left-wing agenda. Jim's had a couple of threads in recent days that make it clear that FR doesn't support Romney. I'm just trying to figure out what that means, exactly, in terms of which discussions will be permitted.
Anyway, I assume that will be cleared up over time by us seeing which posts are being zotten, and which aren't.
None of us will see all of the zots. Most of us won't see most of them. Some might not see any. Also, the zot button is not always applied in a perfectly scientific manner. This is a big issue and it will only get bigger as the election heats up (and it certainly will). I believe an edict from high atop Mt. FResno is in order.