Negative peace is the absence of violence, whereas positive peace is the presence of justice, equity, and peace-fulfilling structures.
I think leftists could have a much more productive time explaining their philosophies by advocating for positive peace instead of negative peace, and highlighting the terrible latent violence that comes from a systemic injustice, like people dying from a lack of healthcare.
It's what makes acts of political violence hard to reason about. Charlie Kirk was a horrible person, and he advocated for quiet violence, by advocating for gun rights and championing pro-gun agendas, he is complicit for the murders that have been wrought through gun violence. An act of viiolence against a political advocate like that is not actually an act of violence, but rather a conduit of the latent violence he encouraged and nurtured.