Generally speaking, triggers are internal or external units of experience, that align in some way, with our previous traumas. These triggers lead us to begin to re-experience the pain, confusion, and compulsions to protect our self, that accompany conscious, or partially unconscious, traumatic memories.
Most folks entire motivation for being offensive (racists, karens, etc) is to reduce us to this:
They know how to push buttons to elicit a self affirming response.
Its their own insecurities at work because (just by going about our lives / minding our business / being successful at anything) we don't appear to be playing by the rules of their game.
Notice how a racist never has a problem with the poor, ignorant, deaf, dumb, and blind, of us.
Only those of us who do not conform to their sense of superiority become the targets of their intentions.