I'm not advocating for being uninterested in the shit they are doing. I'm advocating for being uninterested in taking their stupid claims seriously.

To literally, actually be offended like an adult and seriously treating them like the lunatics they are.

If you are on a stage or a room with them and they spill this bullshit, demand they be removed. Be absolutely adamant, in a calm but still incredibly angry fashion. Like how the entire room reacts in "12 angry men" when the racist finally says what he dog whistled all the time. The kind of outrage that doesn't require shouting or screaming because you are simply right and they are simply wrong and despicable.

It is a special kind of behavior that indicates everybody involved, on an emotional level, that they have crossed a border which will designate them as unsocial, as not part of a civilized group.

You must demand civility or outcast them. You must establish bounds that you will not compromise. It's the only language they understand, short of violence.