I was going to write this up on RedState, but streiff beat me to it. Let me sum up the situation as follows:
Essentially, if you’re not a Republican, you’re not voting in the Republican NY primary. The thing is, though: New York has fusion voting, which means that candidates can run under multiple party ‘lines’ and combine the totals. The practical result from is that minor parties thrive in New York (almost 30% of voters). The only drawback to it, from the voters’ point of view, is that the system breaks down when you do Presidential primaries – but, hey! When was the last time the New York Presidential primary mattered at all in an election cycle?
PS: I have absolutely no idea if anybody’s explained this yet to the likely winner of New York (who will still probably win NY), no. Or to his acolytes. I kind of hope not; I’d love to see his reaction.