Many liberals hold onto the dream (basically a religious belief, given the overwhelming evidence to the contrary) that humans are basically good, therefore all the evil being commited humans must be the result of evil objects corupting them. In liberal dialogue, you NEVER hear an individual blamed for their actions. If It's not guns, It's poverty or mental illness. The closest liberal come to blaming individual are when the call them racist (or any other ist) or trasphobic (or any other phobic), but even then they are just blaming the broader ideas of isms and phobia and not the individual.