Fair; have tried to combat this issue in a few ways.

Each model's position is scored against outside political-science data (Chapel Hill Expert Survey for party positions, World Values Survey for where populations sit).

The stance coding is done by a separate model with a published prompt + a second model from a different lab re-scores a sample and we publish where the two disagree.

So not perfect but (as far as I can tell) one of the more defensible approaches.