Who handled this all properly, in similar circumstances, not exactly the same circumstances, were the Seattle police. Seattle is often called a liberal city but Sunday, their police did do right.
They pepper-sprayed the counter demonstrators.
Just because some side marches whose ideas are repugnant, does not mean that they deserve to be treated in any manner.
Look at the pride parades. Some of those parades get very raunchy I understand. What if it was a parade of something repugnant like satanists or pedophiles, etc. As bad as their ideas are, if they have a permit, they have a right to free speech and demonstrations. It would not be okay for some counter protest group to go in and rough them up because their ideas are so repugnant.