But in addition to that extremely reliable and enthusiastic vote are a lot of allies who say things like "I'm not racist but...". Often followed by "I just happen to have totally non bigoted reasons to always vote with the bigots".
Funny how they're always espousing Republicans as the way to go. Once upon a time, that may have made (some) sense, but the modern Republican party is ... "not very close" ... to libertarianism.
Therefore in a two party rule, libertarians should do what they can to pit one arm of the government against the other. Sometimes this will mean voting D, and sometimes R, whichever better disrupts single party rule.
They "should", but somehow they always seem to find themselves voting R...