On April 1, the Wyoming Supreme Court unanimously upheld a 2023 law that says voters who change party affiliation during the 96 days before a primary cannot vote in that primary. Malcom v Gray, S26-29. The decision says the law does not violate the State Constitution, because it is necessary to prevent “party raiding.” Here is the decision.

The law was passed following the 2022 primary for U.S. House. Incumbent Liz Cheney was defeated in that primary by Harriet Hageman. A large proportion of Wyoming Democrats had changed their registration to Republican weeks before the primary, so as to help Cheney. That didn’t work to save Cheney, but it motivated the legislature to pass a law making that behavior impossible, unless it was done very early.