Why Do Conservatives Accuse Everyone Of Marxism & Nazism So Much?

Anyone familiar with politics online has encountered the very common strain of right winger (some are "libertarians" instead of conservatives, but I didn't want to burden the title too much) who run around equating all forms of left wing politics from liberalism, social democrats and other soft-socialists to full bore Marxist-Stalinists, Maoists & (of course, nonsensically) Nazis & fascists.

Why do they do this?  I mean, the distinctions between left-of-centre politics as practiced in the entire rich world set of democracies and those totalitarian ideologies are glaring and numerous.  It can't be persuasive to anyone who can just look at a European style welfare state and realize whatever the faults, there aren't gulags, reeducation camps, political thought police, single party rule, abolition of private property, emigration controls and on and on.  Add to that the obvious general prosperity, happiness, health and long life in most such states and it's really boggling to reconcile on any kind of conherent or intellectually honest line of thought.

I'm sure many such people who make these absurd claims really don't get it, and actually can't see the distinction between liberalism and Stalinism (nevermind fascism).  Mostly though, this comes from their manifest inability to really argue against the outcomes of reasonably successful welfare states.  The people are mostly happy, well fed and prosperous.  It's not perfect, and you can imagine many criticisms but it's really not that bad.  Nothing about it aligns with the kind of catastrophe they're always predicting from any policy deviation from hard core laissez faire economics.

A fictional movie President of the United States (Michael Douglas in the speech at the end of The American President) called this when he said of an opponent:

I've been operating under the assumption that the reason Bob devotes so much time and energy to shouting at the rain was that he simply didn't get it. Well, I was wrong. Bob's problem isn't that he doesn't get it. Bob's problem is that he can't sell it!

This sort of right wing hyperbole against the liberal welfare state & interventionists government has long roots going back (at least) to 1944 with the publication of Friedrich Hayek's "The Road To Serfdom."  1944 was a long time ago, seeing as we're not at "serfdom" yet (and really right wing neoliberal economics is what threatens to make serfs of most of the population if anything does) it's got to be one hell of a very sticky & gentle "slope" we're on here. 

Let us know when Norway implements single party rule, but until then this is just another right wing effort to reinvent reality to suit their myths.