What NY is running is a very fair process. I don’t like the situations where party members don’t have primaries to vote for candidates. Open primaries are an equally bad idea, at the other extreme. It seems totally reasonable that a person should have to be a member of a political party a month (or more) before the primary. That way, the party has time to make sure every party member has equal access to information about how delegate selection will be done. Another benefit is there can’t be any mischief such as “vote for the worst” or what happened to steal that nomination for Cochran.
Sometimes, that can blow up in your face – see 'operation chaos' as a great example.
I agree with closed primaries, registration and party change deadlines are reasonable. I do see an issue if some had their party affiliation changed by someone else so they cannot vote, not sure how they would prove that but sounds like shenanigans.
I guess there is always a way to cheat, that is the real issue.
But at least better than the fiasco in both CO and in WY.