The Libertarian party is to the GOP, what the Green party is to Democrats.
Actually the libertarian party is much worst to the GOP then the green party is to democrats. The green party would never vote with republicans but would simply just vote third party. There are many so-called libertarians who vote democrat and in every war since Viet Nam there have been libertarians marching side by side with Marxist against the United States. Libertarians also side with social Marxists on many issues as well.