Actually my assertion is that from an outside prospective looking into the US, compared to the political movements in other countries, we are all centerists.

I.e. While people in the US percieve that we have a broad political spectrum, our spectrum is very narrrow in comparison to what you find in other countries. For example, many other countries have actually viable Communist parties, and actually viable Facists parties. As much as we toss theses words around when trying to label the "other" side both sides Democrat and Republican fall far short of these labels as seen from an outside observer.