There is a bit of an apples to oranges comparison here. Hamilton was talking about the election to office, not primaries. Party primaries are actually a fairly recent change. I don’t have the exact date, but the parties used to select their candidates only via caucuses and conventions without any primary election as many states have today. Political parties are private organizations and can make their own rules as they see fit.
What we have been seeing in the Republican Party is gross manipulation and betrayal of their members. The party members are rebelling. What they are doing may or may not be right, but it is neither illegal nor in violation of the constitution or any law.
Part of the upset is because most voters never participate in primaries and there are a lot of new people participating this year, and they do not know the rules.
It may well be time for the Republican party to go the way of the Whigs, and be replaced by a new party. But let’s not add to the confusion and be diverted by immaterial issues.
The first primary was in Oregon in 1910. Pushed by the Progressive Party.
Maybe a party without any of those pesky rules? Where the will of the Dear Leader is the only "rule" that counts? What a terrific idea! Lunga vita al Duce!
But please, don't anybody tell the Trump fans.