the truth is that the idea of a linear political line (right to left) is quite incomplete... the better model is a graph which has two axis... x axis for state involvement in social issues (personal), and y axis for state involvement in economic issues.
This chart has been used most effectively (and propegandically) by US Libertarians - check out this link: (http://en.wikipedia.org/wiki/World%27s_Smallest_Political_Quiz)
The 'smallest quiz' test questions are very leading and its quite a badly designed set of questions for real social science research, but the two-dimensional model itself is rather impressive (and simple).
the issue of why 'fascism' and 'communism' come close in some minds is that they are both forms of statism... where as one envisions complete state control of the economy (Communism) the other envisions a complete state control of social/personal behavior (Fascism). There is certainly some overlap, but because nuance is lost to so many in the 'nut-job' fringe on the right, these details are irrelevant.
most of these 9-12ers or birthers, or shouters that are dominating the Republican party of 2009 in the US are rather close to Fascists themselves and pretty far from being libertarians... because they WANT the state to control personal behavior (ie abortion, church, and other social issues) but they want corporate control of the economy (minimal to non-existent regulation, opposing a progressive tax system etc).
I enjoy talking to libertarians, as they are for the most-part logic-based... their basic problem, and I pity them this, is that they have NO political party to call home. Real libertarians who do not condone corporate welfare also don't want a theocracy... so they really are an ideology without a political home in the US (that's why Rep./Dr. Ron Paul is so marginal in his own party).
anyways... one thing that has become clear to me over the years, is that in every society you will have 10-15% of the population that are just nuts (even France has Le Pan) and though a few will eventually recover or manage to break free of their own mental chains, most wont. the key to a healthy society is making sure this fringe stays as far away from the levers of power as possible. in my country of birth, Iran, that is the problem... the same 9-12ers and "Beck-is-God" crowd that rejoiced at the "You Lie" line from Congressman Wilson are actually IN CHARGE in Iran's coup-government right now... God forbid these people also take charge here in the US! They are far too close to power as it is.