The disabled guy is an American vet, who sacrificed for his country so that others would have privileges, like freedom of speech, that many parts of the world don't.
Antifa can't win on the basis of the superiority of its logic or history. So it resorts to violence to try to shut down freedom of speech
Democrats are going to pay a political price if they don't come out and start to loudly denounce antifa.
Americans are not going to tolerate any silent support of violence, for folks that stand by and watch without speaking up