If someone hands a loaded gun to someone who they believe intends to commit murder, do you believe that they are not a part of the murder committed?

Well, I'm glad you at least recognize that your solution to bigotry is not practical. I agree that it's a moral ideal, but morality to my mind depends at least as much on effect as intention, which is where practicality comes in, and the fact that showing "unearned compassion" to bigots, at least in the way I typically seem to see that interpreted, just emboldens them and makes life worse for everyone else. The most extreme example of this is, as alluded to, Chamberlain's appeasement of Hitler, but we see the same thing play out on a smaller scale frequently.

Most people who discuss morality with any frequency will probably tell you that whether or not you know the outcome of an action ahead of time does impact its morality. So I would argue, because we know that showing bigots "unearned compassion" rather than societally refusing to tolerate their behavior invariably has a net negative impact on those who are the targets of their bigotry, that would render it not the moral ideal we might like it to be.

Please observe the paradox of tolerance.

You were never apart from society so you are bound by the social contract by default, failure to uphold the social contract will result in the following violence: being put in the corner, being told 'no', spanking, detention, suspension, loss of employment, physical violence, police arrest, incarceration, garnishing of wages, loss of access to social services, etc.