I am a non-member. Every month I calculate my association fee and happily send the check. My EXCO and, when applicable, my Negotiating Committee speak for me and I have no issue with paying my fair share to ensure they continue to do so. You can and should carry your own water.
The fee is about 7% less than full membership dues. That 7% is money that does not go to support the International, which absolutely DOES NOT speak for me.
You should not, either voluntarily or through coercion, support positions with which you disagree. Yes, it is a First Amendment thing.