To date all the Libertarian party has done has been to act as a spoiler for the GOP.
Nope. Not true. Every libertarian vote is an expression of a desire for liberty minded candidates, no matter what party they should appear in. If enough people vote libertarian, the other parties will take notice and perhaps put two and two together. We can only hope.
A vote for a libertarian, therefore, is a vote for those principles which are not being expressed in either of the two major parties. That's a vote
for something. It's not a wasted vote. It says both of those other two candidates are so contrary to my views that I cannot bring myself to vote for them. There is substance to that statement. It means something, and should eventually come to mean something to the Republican Party, which was once the home of Classical Conservatives, the kissing cousins of libertarians.
PS The main difference between classical conservatives and libertarians is the reverence for tradition and traditional institutions such as marriage, family life, church, constitutional federalism and the rule of law which classical conservatives possess. They believe that liberty rests on these pillars. Disturb the pillars, and liberty cannot any longer be supported, or will be less supportable with the destruction of each pillar. That is precisely what conservatives seek to
conserve, i.e., those liberty supporting pillars, thus the name conservative.
Libertarianism promotes liberty, but does not propose necessarily that liberty rests on these pillars, which they do not seek, therefore, necessarily to conserve. That's 95% of the difference between the two world views. They both desire the same general status of political and individual liberty, but have a different understanding of how that is achieved and/or preserved.