On the same website, 59% of the male members claim that their favorite organ has a length of 16-199.99cm. :yim_rolling_on_the_
That link summarizes an enquiry among the users of a libertarian webside. Only 46 members reported their IQ. With 6 members claiming to be over 150 that makes 13,04% of the participants above an IQ of 150. No matter what scale was used (or if all members used the same scale) this is highly dubious. Even on the Catell less than 2% are above 150 and on the Wechsler only 0.13% are over 145, let alone over 150. In any system, that website must be frequented by geniuses.
You will probably meet your friends among your own social circle. If you are a student, they are likely to be student. That influences the average IQ in your environment. And since knowledge of and sympathy for libertarian philosophy is partially linked to access to education and money, I wouldn't be suprised if there really was a certain correlation. But that doesn't mean that they are "right" because their followers have higher IQs. It just means that those favoring every man for himself and no taxation tend to have a good education and a lot of money to tax...suprise, suprise!