It's an interesting dilemna.  I abhor censorship, but there is a pattern I've witnessed repeatedly. 

A *lie* is posted by a Leftist with an axe to grind. The lie is refuted, the facts demolish all credibility of the lie and the liar. The following day, the lie is *REPOSTED* in twelve different threads, and the liar complains to the board's moderators that the refutation of the lies is harassment.

Truth be told, I DO NOT KNOW what the appropriate cure for the above problem is.  What I do know (from personal experience) is that after several rounds of the above, the reputation of the poster who has the truth to fall back upon (me),  tends to result in one of two typical outcomes: 1) When the mods are honest and the forum is impartial, the liars tend to get banned, until they assume new monikers.  2) The mods ignore the lies, (maybe) ask the abusers to stop the duplicate posts, or freeze the threads with the lies in place and the rebuttals frozen out.