I'm NY. The idea is that an open seat primary gives us a BETTER chance against the two party machine, since far fewer people vote in them than in the election, and the incumbent isn't running. It doesn't eliminate the big party machine guys, but catches them in a much more vulnerable position, since the machine candidate is not as established as an incumbent. The Tea Party even showed that, if charged up enough, reformers could even oust many incumbents in the primary.
What the movement needs to learn to do is to farm candidates whose "motor is running," once an opening arises, and in the case of the LP, ask them to be ready to serve as "switch hitters" to run for a Democrat or GOP seat as they come up. Couple that with a "motor is running" liberty voting bloc in the state, that will be kept up to date on liberty issues and contenders, and you'll have the base of supporters needed to rally around a liberty campaign when the open race situation arises.