It seems to me that there are deep and bitter divisions on the Right, between social and religious reactionaries, business-interest "conservatives" (actually liberals or Whigs), police-state conservatives, and libertarians, to the extent that they hardly speak to one another. They have been united in the past only by their hatred of Left and those aspects of the established order which betray leftist influence, e.g. democratic elements in the government. Those who try to bridge the gaps, like David Horowitz as a matter of fact, do so by sticking to vague, abusive, usually stupid polemic. At one point in the past I tried to engage Horowitz in the Salon chat pages, where he sometimes appeared, and he invariably shied away from rational, factual discussions of specific issues in favor of flammage. I think anyone else who witnessed these exchanges would agree -- even DH himself might agree, since he seemed to think that abuse was an interesting and valid form of discourse called for by the urgency of the situation (politically correct Stalinist anarcho-egalitarians running amok everywhere).
As for purity tests, I'm all for them. The Left is the side of freedom and equality. Acceptance on the Left of authority, militarism, class systems, and so forth has allowed its -- our -- enemies to portray us as thugs and slavemasters, to their considerable advantage. If the salt has lost its savor, wherewith shall it be salted?