‘Mostly peaceful protests’ are like the ‘moderate rebels’ in Syria – propaganda constructs that do not exist in the real world. The people who owned the burning cars and whose businesses were destroyed will not be relieved by such phrasing.
Joe Biden’s attempt to swing Republican voters to his side has failed. At the same time he has rejected many of the issues progressives favored. This will hurt the election turn out the Democrats will need. Add to that the unrest which plays into Trump’s hands. The Democrats who fear that are right: