Sadly it's already happened, years ago. Even before I was born. My high school Latin teacher was an anti-war college student in the 60's around the time I was born. She told us how her very peaceful campus group was harassed and under constant FBI surveillance. I wish I could recall her exact words and account for you.
I lived briefly in a very liberal town that was kind of a throwback to the California hippy communities of the 60's-70's. Many of the residents were strongly anti war during the Bush-Cheney era and some of them would gather in these little town meetings to just complain about the war and discuss where and how to distribute "War is Not The Answer" lawn signs and other peaceful protest stuff.
They were the most unthreatening people you could imagine. Well anyway I was quite surprised to find out that these folks were put under surveillance by law enforcement which actually sent spies in to watch these meetings and build dossiers on the most boring peaceful people on earth.
I can't find an electronic copy of the community newspaper in which I first read that article but here is one about similar surveillance programs on people who dare to protest such things as the death penalty or animal cruelty by making puppets. Oh the horror. These terrorist puppeteers must be stopped!
http://www.washingtonpost.com/wp-dyn/content/article/2008/07/25/AR2008072502530.html
We live in a police state as surely as the Chinese and Russians do. I hold no illusions about that. All you have to do is join a group that dares to complain about our government's questionable wars or how the government sides with big business in a way that hurts living things and boom...you're a person of interest. I found many many other articles detailing such programs of domestic surveillance but I'm not familiar with the reputations of the sources so I didn't link to them.
What boggles my mind is that while we have all these self important Barney Fifes keeping such a close watch on boring people who dare to have an opinion, a man who actually had a clear dangerous mental disorder who once made the effort to go out of his way to get the attention of the authorities was given his gun back and thus we had the horror at the airport we just witnessed. I see no evidence that our police state exists to do more than keep itself supplied with money and power. Not if our death toll from mass shooting events is anything to judge by. I'll try and be generous and give them the benefit of the doubt that they've shut down many terrorist endeavors I'm not aware of.
While I have the same concerns you do, I think you're drawing a false equivalence by saying "We live in a police state as surely as the Chinese and Russians do."
In Russia and China, political dissidents are rooted out through social media, hunted down IRL and imprisoned, shot dead spectacularly in the streets, or simply die under mysterious circumstances-- sometimes across national borders. If they can't be found directly, their families are used as leverage.
We aren't that.
The ACLU was handed the documents. The WaPo published the article. State Senator Raskin wasn't disappeared for sedition.
As far as I can tell, most of the surveillance activity was still security focused. I don't like it, I think it's misguided in a lot of cases, and I think it's easy to find specific instances where over-zealotry reached absurd levels. At the same time, I like the fact that the FBI monitors the mafia, and we know there have been cases where domestic political terrorism has taken a lot of lives (McVeigh, Kaszynski, Breivik, the IRA, KKK and SLA, etc...). Lately the violence seems to come from the right, but it wasn't long ago that it came from the left.
I expect the government to try and prevent domestic political violence and to do it in a way that doesn't distort domestic political action. That's a really hard line to walk, and what is warranted and what isn't will be colored by our personal political convictions. One side may think it's obvious that people protesting the death penalty wouldn't hurt innocent people, while the other side may think the same about people protesting for "the right to life". It's hard to know when the right combination of passions and mental instabilities are going to find each other and it always looks like incompetence when the good people are hectored and the bad people slip through unseen.
Ironically, I prefer the surveillance be under cover so long as it remains focused on security only. There's a big difference between a mole sitting on the sofa writing reports that "No intelligence has been gathered at this point that there are any illegal or disruptive actions planned", and what you see in places like Russia where police and security services in uniform stand in the open with cameras and video recorders capturing individual participants. Which do you think will have a more chilling effect on political action?
I had the kinds of incidents you're describing in mind when I said that I do worry about what we could become if the apparatus is placed in the wrong hands. Many western democracies have built what I often call a "turn-key police state".
J. Edgar Hoover crossed the line without a doubt.
I'd say that the Bush administration walked right up to the line for a few years, but I don't think they crossed it domestically.
I do think innocent people have been swept up in security drag nets, but I think it is largely the result of ignorance and the inevitable result of whatever you call the law enforcement version of the fog of war, rather than an attempt to use the powers of the state to crush political opposition.
I also think the incoming administration has pretty clear authoritarian tendencies and I think there's cause for concern when handing them the levers of power, but a lot of individual people and institutions would need to be compromised before the US as a nation passed fully into the darkness.
Vigilance is important in ensuring that the state doesn't abuse the authority we've given it, and publicizing the missteps is an important part of that.
My concern though is that implying we are, today, the same as Russia and blurring the distinction between surveillance as a means to prevent political violence and surveillance as a means of perpetrating political violence is unhelpful rhetoric.
If I were Russian or Chinese, I'd be much happier if my political views were held in a database in San Francisco, London or Amsterdam than in Novosibirsk or Shanghai. Coming from a western democracy, and frequently traveling internationally, I feel that way in fact.