@Blickers,
Blickers-
Thank you.
I live in New York State and my understanding is that to vote in a political party's primary, one needs to be registered in that party one year or more prior to the primary election.
I think (I'm not sure) that it depends on the rules of the particular State political party.
The reason for my question was that I wish to ascertain whether Trump did worse in the primaries of the States that require a relatively long membership in the party prior to voting in a primary election.