Yet it is you that proclaims the middle of the road people support Antifa.
You made that up.
As to burning some random post office, sure, let's deprive a whole class of people of their liberty for the acts of one or a few. Then we'll list the NRA because one member committed a firearms related crime. The libs would be all over that.
Again, the sauce for the goose is sauce for the gander attack. On a rational basis, stating universal principles, distinguish the two cases. Can be done but nobody has yet.