Why do the US and UK only vote for Authoritarian Right Partys/Leaders?

[PS360ForTheWin]

Why do the US and UK only vote for Authoritarian Right Partys/Leaders?

do you know why?

http://www.politicalcompass.org/usprimaries2008

http://www.politicalcompass.org/extremeright

according to this (and my own knowledge of parties policies) neither the UK or US has a party that can be elected that will be Libertarian Left (same site says is my position)

So My Question is why?