Free Republic has always had its share of political trolls since it started. Eschoir is one infamous historical example.
We have had the Paulites, Rovians, and that span of Crevo madness about 10 years ago that just got out of hand (probably had a good number of crypto-Libs intentionally out to make this site look bad-wouldn't be surprised if they had some sock puppets pretending to be creationists just to generate thread after thread of crap).
Several posters way back were outed as being campaign operatives, while some were very up front about who they were (I'm thinking folks like Tony Snow R.I.P. and some others).
What I watch out for now as garbage are the pure candidate advocacy type posts and those that blame "conservatives for every Republican loss because they stayed home or didn't vote for "X"".