We need to fix this problem and keep folks who are IN other parties OUT of the primaries, whether as voters or candidates.
Even those who worked for Democrat campaigns, or contributed to Democrat candidates should be flat out banned.
You have absolutely no idea of what you speak (or write) with respect to Libertarians. Without voters who are generally ideologically libertarian, the Republican Party would be nearly indistinguishable from the Democrats and have no chance of winning any national election.