Listen to any Republican, and they will tell you that it is Democrats who increase the scope of government, erode freedoms, and take us on a slow path to tyranny. This is what they have been led to believe (by Rush Limbaugh and others), and so it should be no wonder that Democrats are considered a form of watered-down Fascists.
Listen to any Democrat, and they will tell you that while they do share some minor similarities with Communists in valuing equality, it is Republicans that think in hierarchical, societal-role-based terms, and therefore it is Republicans that share more in common with Fascists. This is what they have been led to believe (by Alan Colmes and others), and so it should be no wonder that they arrange the political spectrum the way they do.
Stop thinking in spectra! Political variation is not one-dimensional and implying associations between your fellow citizens and totalitarian regimes is not helping. Criticize officials on the policies they actually endorse, not on the policies of vaguely similar parties from world history.