How, exactly? I mean, it's not like the rioters are following his orders (or maybe you're saying they are?!). If you're just saying it's his responsibility, then sure, but he's not the only one. Aren't community leaders, the police, the governor and the president likewise "allowing" the riots to continue simply because they haven't stopped them?
I mean, Trump literally evoked an image of shooting rioters. Did anyone else do anything similar?