It's true, and there's more than one way to make it rational. Victor Davis Hanson is registered as a rat.
There's only the rat party that controls the CA state offices.
I could be wrong, but any registered voter can vote in your primaries. Correct me, if I'm wrong.
They have more potential than is readily appreciated. They can help push a leftwing moonbat that will be rejected by the electorate in the general election, or help a more moderate rat in the general election. In most gerrymandered districts, they don't make a differencce.