I've never understood this line of reasoning. No matter where you run the head bashing police state will follow you. They're operating under increasingly ruthless and vindictive societal norms and they're becoming mostly immune to serious life-altering repercussions. They couldn't care less if you scream or shout or photograph them or not. We've seen this before and deep down we know where it ends, but I guess acknowledging that reality is harder than pretending you can stop and prevent it simply by choosing a different transportation method. What a bizarre angle from which to post this story. This is neither the time nor the place to spin the story in order to plug travel on Amtrak.
This was a blatant abuse of power which followed a chain reaction of stupidity on the part of the airline, staff, and policies (keeping in mind there is much we don't know), but in no way does it equate to a 'police state'. And while you are correct in that it is most certainly not an appropriate plug for rail transportation, it is also true that you actually can still avoid such excessive 'heavy handed' and uncalled for treatment by an alternate mode of transportation. The degree of security and expected strict compliance of air travel has not (ordinarily) found its way onto trains, buses, or your private automobile. If the hyperbole is so great you call America a police state, what do you then call North Korea?