Why are so many US States a closed primary state?
It would seem to me that closed primaries are a big issue with politics in the US.
Primaries are by and for the parties themselves. They get to set the rules for how they determine what candidates they put on their tickets. I have huge issues with the existence of political parties in the first place, but as long as they exist, if they want to restrict that decision-making to party members only, I don't see any real issue with that. It's not like we're talking about the actual election here.
Why? It's mainly so people of that party are the ones choosing the candidates for that party. Without closed the other side purposely tries to sabotage the otherside by voting for the worst candidate.