The important thing is to know and be committed to your own values clearly, so that when someone comes along trying to get to involved in things you don’t support, you can recognize that just because they’re acting friendly or want to be your ally, that doesn’t mean it’s a good idea.
The end result of everyone doing that is the kind of isolation you’re referring to. Doesn’t need to be centrally coordinated; the group just isn’t fertile ground for the extremism any more, because the members of the group know what they’re about.
The important thing is to know and be committed to your own values clearly, so that when someone comes along trying to get to involved in things you don’t support, you can recognize that just because they’re acting friendly or want to be your ally, that doesn’t mean it’s a good idea.
The end result of everyone doing that is the kind of isolation you’re referring to. Doesn’t need to be centrally coordinated; the group just isn’t fertile ground for the extremism any more, because the members of the group know what they’re about.