I just got a republican AND a democrat primary ballot in the mail.
4 years ago I left party affiliation behind. I was done. The same year the Colorado electorate voted to an open primary instead of being a caucus state. So while I declared I wanted nothing to do with either, I now get to vote for who they have as their candidate. I have more influence than Republicans or Democrats because I can choose whose primary to influence. Trump is obviously going to win the Republican primary, so it only makes sense to vote in the Democrat primary.
I think the open primary arrangement is a bad idea. Why should I, unaffiliated, have more influence that those who affiliate?
@sda
I guess that's related. They aren't in the constitution, aren't part of the government. Why are the party elections even officiated by the government? If a group wants to gather like minded voters and pick a candidate to support, let them do it by their own mechanism, open out closed to non members, etc.