It’s about more than voting blocks. In a 1975 interview with Reason no less a conservative than Ronald Reagan said, “If you analyze it I believe the very heart and soul of conservatism is libertarianism.” Now, obviously the power dynamics and constituencies are different these days, but the truth is the more Republicans win, the more the philosophical backbone of the party seems to weaken under the understandable if not particularly admirable desire to hold onto power. So libertarians may not win Republicans elections, but it’s difficult to look at the behavior of this Congress and White House without getting the sense that we could use a little more principled opposition in the ranks. Right-leaning libertarians carry more worth than a simple vote.
Here’s more Reagan from that interview, by the by:
The basis of conservatism is a desire for less government interference or less centralized authority or more individual freedom and this is a pretty general description also of what libertarianism is. Now, I can’t say that I will agree with all the things that the present group who call themselves Libertarians in the sense of a party say, because I think that like in any political movement there are shades, and there are libertarians who are almost over at the point of wanting no government at all or anarchy. I believe there are legitimate government functions. There is a legitimate need in an orderly society for some government to maintain freedom or we will have tyranny by individuals. The strongest man on the block will run the neighborhood. We have government to insure that we don’t each one of us have to carry a club to defend ourselves. But again, I stand on my statement that I think that libertarianism and conservatism are travelling the same path.