He encouraged people not to wear masks as a lifestyle choice and cultural signalling thing. Some % of transmission rate is directly attributable to him -- he could have said wearing a mask owns the libs and massively helped instead of hurting.
The final verdict on the efficacy of masks against this virus is still TBD once we have more information and the passage of time removes the political agenda's that cloud this conversation. Your "own the libs" certainly doesn't help either.
Though IMHO, given the role vitamin D deficiency seems to have on mortality rates, I think the harshest criticism (charges?) should be reserved for any mayor who ordered tanning beds to close in his or her city.