The problem with this line of thinking is that if anything but total purity is rejected, then your side of the line in the sand is quite small in comparison to the other side.

I agree in theory that human rights are non-negotiable. But in practice, movements need popular support, and that support relies on compromises.

In my view, fascism is the unionization of all groups and individuals that a democratic society considers to be immoral. The harsher a society is in its moral judgements, the larger the "out group" becomes and thus fascism grows stronger. This is not a moral question, btw. It is a simple question of cause and effect. In a perfect world there would be no fence-sitters or bigots. But we don't live in a perfect world.