The Republicans in MN are being total jerks about the possibility of changing to a primary. The Dem leader is all for it, but the Repub leader insists that even if they WERE to have a primary, it would still be non-binding and the Republicans would just choose their delegates at the state convention.
Republicans are just hopeless, and I really hope everyone else railroads them and does it anyway.
In WA it is the opposite: the voters had an initiative and set up a state-run primary, the Republicans decided to recognize the results for some of their delegates -- the Dems are not using the results at all, they are sticking to their caucus system.
So the local party can over-ride a state ordered primary if they want to.