BS.
He’s free to run as an independent or get a sign off from the political party leadership to represent THE POLITICAL PARTY in the PRIMARY.
This isn’t the general election - this is the POLITICAL PRIMARY and he wants to party hop to spoil the ballot.
If he’s sincere than he should have no problem getting the sign off from political leadership - but he’s not. So he’s free to run as a Democrat or just as an independent.
POLITICAL PRIMARY
Rust is challenging a state law, not a party rule. That said, I do understand that a large segment of the American people want to limit candidate ballot access for political reasons.