Get Real:

Remember a little firestorm which incinerated men, women and children at Waco?

And that was under a supposedly "liberal" Democrat president.

To suggest that the last half of the 20th century hasn't seen any abuses by government forces (and the long arm of their civilian paramilitary/vigilante groups), there has been plenty of violence used against civilian groups:

Kent State in Ohio Fred Hampton murders in Chicago SLA house in California MOVE house in Philly

and those are just the quick ones off the top of my head.