Even very liberal people question the use of fluoride these days. In my country, we are pretty liberal and almost all people here hate republicans. The biggest country's city where I live has banned fluoride in drinking water a long time ago since we get enough simply by brushing our teeth so there is no need to ingest some every time we drink a glass of city water which is pretty good by the way. I simply put some city water in an open container in the fridge and let the chlorine evaporate (fluoride don't evaporate).
Please review your data, there are plenty of liberals against fluoride and the ones still using it are behind and probably corrupted by the fluoride provider industry.