Do you think that the Democratic Party is dead to liberty? Isn't the Democrat Establishment only slightly worse (or better) than the Republican Establishment? What makes you think that the displacement of the Establishment in one party would be any easier than it would be in the other? The Neocon mafia and the Rahm Emanuel types are cut from the same cloth.
You'd stand just as good of a chance, by attacking the duopoly from the outside, and knocking off one of them—it doesn't matter which one—as you'd have in trying to coopt one of them from within. The duopolists' big lie will be, with obvious self-interest: "Third parties never win." The reality, however, is that a new party succeeds in establishing itself about once a century or so. We are overdue. You would be putting your energies to better use in the building a new, genuine "Libertarian" party. A successful American Libertarianism would serve as the leading edge for an international movement of Libertarian parties.
I find it hard to believe, that a new political generation is going to spend its youthful energies, in simply cleaning out the garage for the preceding generation(s). It might very well do that, but that would be a waste.