You will always have that kind of extremism and hyperbole from one side or the other regardless of who is in power. As much as I hate it, it is the nature of politics.
I dunno. In the USA, the republicans and the right in general will not think of allowing the far right--the KKK, the American Nazi party, etc.--to join them. The left, however, in its anti-war marches, DOES allow A.N.S.W.E.R. (a Stalinist group) or half a dozen other nutcase groups to march with them.
Imagine the outrage if, say, the head of the Republican Party said something like: "well, yes, some KKK members showed up in robes in our rally, but just because we disagree with them on some things doesn't mean we have a common ground to oppose the deomocratic party's tax-and-spend policies". Yes the left excuses the presence of ANSWER and others in just such terms.
And don't tell me this is a matter of "free speech"--as the article Ziggurat published shows, there was rather ruthless supression of it during the rally for those who didn't agree with it.
The fact that ANSWER & co. were allowed, and even encouraged, showed the real issue in question was NOT "anti-war" or "peace", but merely hatered of Bush, personally, for whatever reason.
The reason, I think, is that Bush--and the "neo-conservative revolution" in particular--signifies to them the fact that they are irrelevant, and they hate that. How come all those STUPID people had to vote AGAINST the candidate I like?!, they think to themselves. The epitome of this attitude is the New York socialite who claimed the war on Iraq couldn't possibly be popular--nobody she knows supports it.