Conservatives can surely have heated discussions among themselves. Where this ceases to be useful, IMHO, is where the point starts to be made that 'anyone who holds viewpoint x is not a true Conservative', as in the recent rash of 'Darwinism is Marxism is Naziism' posts. At that stage, one can hardly expect the targets to resign themselves to playing defense; rather, they themselves are likely to look at the credentials of the self-defined 'True Conservatives'. Thence the foodfight.
This has gotten worse recently, but it has always been a problem. Evos have done an awful lot of ignoring over the years. Almost all of us ignore f.dot, whose posts, if you actually take them seriously, are quite frequently hateful and occasionally obscene. There has been an organized campaign to ignore ALS and a cohort of the like-minded he has tracked in. However, threads are still getting killed or relegated to the backroom. At some stage, some self-policing has to be done. These people are posting, whether you like it or not, in your name, and profess the same beliefs you do. Unfortunately, Alamo-Girl, you are not the typical fundamentalist Christian on this forum.
The point that is made with this observation is a critical one. It has reminded me of a tactic that I am witnessing elsewhere where radical Leftists and Greenies pose as Constitutionalists insurgents into the Libertarian movement attacking Capitalism and driving wedges between Objectivists and Conservatives. I've exposed such sappers enough now to believe that it is more tactic than coincidence. In the case of Capitalism, it is impossible to defend Constitutional liberty without legitimizing Capitalism... afterall that is the fundamental connection. This becomes a fatal flaw for 'sappers' by which they expose themselves.
I am not suggesting conspiracies here, just possibilities based on experience. Either way, I agree with both of you (RWP, and AG) that the extremes of either position are not dangerous in themselves. Afterall, someone must defend the fundamentals of a principle in order for it to remain as such. The danger arises when those fundamentals transend a basis for principle and are used to 'filter' thought. That is when fundamentalists become extremists undermining the same principles they seek to defend. And often times, they become tools of destruction at the hands of a lurking and sly enemy.