You don't even have to be registered to vote -- so how could you use voter affiliation as a check?

As I understand it, you have to be 18 by election day, and sign the Dem affadavit. Since both the D and R caucus rolls are public, and double-voting is a felony, you have a pretty strong incentive not to do so forcing you to choose, at least for this cycle, which process to participate in.