>One’s religious, artistic, or personal values can’t have any political authority over others who don’t share those values. What has political authority is reason, more specifically, those principles which can’t be reasonably rejected. Those are our moral principles, which any legitimate political and legal institution needs to be based on.

This just sounds like you lack self-awareness of your own biases. Because all moral principles are at base personal preferences. Politics is always about whose values get to be imposed on everyone and justified as "reasonable". Religion only fell out of favor as a good source of such values because society changed to quickly to keep up, and so it lost too many adherents to make its influence stick.