All I’m trying to say (badly) is that the pollees will include a lot of “Party first” people.
Polls of those people are important and very useful, but different.
But since they don’t say just what their methodology was in this case they could have just random-dialed.
No worries. I think you are correct. The board is populated by establishment R’s. If there is bias it is in the direction you say because I doubt they are capturing new voters Trump is pulling into the R primary.