[Dr. Sivana]

When Reagan ran all the primaries were closed. Only registered republicans could vote in primaries for the republican nomination.

Not true. MANY states don't even have formal party registration, so it would be impossible to have a closed ballot except maybe in the form of a caucus. Reagan DID get a lot of crossover votes in '76, and the Ford people complained about it. The Reagan people pointed out that the same people who complained that Reagan wasn't electable in the general were now complaining that too many Democrats and Independents were voting for Reagan in the primary.

[BlackElk]

Not gonna happen but the simple answer lies in party rules which the SCOTUS ruled in 1972 override even state laws. RNC passes a rule stating that any state GOP allowing any person not a registered Republican to vote for any GOP delegate in any capacity at any level will be a state GOP deprived of ANY delegates to said convention.

If a state (like Illinois) does not provide for party registration of voters, it will be the responsibility of the state party to do so OR ELSE. Probably needs minor fine tuning but that will work.