So realistically, what can we, the populace, do?
Fight or flight.
1) Speak out, set up organizations like the EFF or similar to fight for privacy. Or advocate on behalf of such organizations. Work the politicians however you can, to whatever extent that might help. Encourage the people you know to do the same; encourage people to give a shit again. Explain why it's important to fight this.
2) Try to leave the US, or at least begin disappearing yourself. Leave less of a trail. Communicate as little as necessary over the phone or digitally, and keep it strictly business (so to speak). Use good encryption wherever you can. Encourage the people you know to do the same.
Either option is valid, both are entirely personal, moral choices. Some people stayed when the Iron Curtain went up in Russia and tried to fight it, some fled; ditto Germany, China, Vietnam, Venezuela, Cuba, and so on.
Unfortunately, one of my senators is Dianne "It's called defending America" Feinstein, and she's got her job for another 5 years, so I'm not expecting much in her case.
If you want to change the US at this point you're going to have to do what the founding father's did: become the government you want.
"And how we burned in the camps later, thinking: What would things have been like if every security operative, when he went out at night to make an arrest, had been uncertain whether he would return alive and had to say good-bye to his family?
"Or if, during periods of mass arrests, as for example in Leningrad, when they arrested a quarter of the entire city, people had not simply sat there in their lairs, paling with terror at every bang of the downstairs door and at every step on the staircase, but had understood they had nothing left to lose and had boldly set up in the downstairs hall an ambush of half a dozen people with axes, hammers, pokers, or whatever else was at hand?
"After all, you knew ahead of time that those bluecaps were out at night for no good purpose. And you could be sure ahead of time that you’d be cracking the skull of a cutthroat. Or what about the Black Maria [Government limo] sitting out there on the street with one lonely chauffeur — what if it had been driven off or its tires spiked.
"The Organs would very quickly have suffered a shortage of officers and transport and, notwithstanding all of Stalin’s thirst, the cursed machine would have ground to a halt!"
* The minimum gun is a military grade bolt action rifle with a 5 round or greater magazine, anything like the Mauser 1898 (sic) or the many guns inspired by it or that evolved in parallel. The last remaining cheap, military surplus ones are Mosin–Nagants (you should be able to get one for $150 or so, just make sure to buy non-corrosive ammo). Buy Jeff Cooper's The Art of the Rifle (http://www.amazon.com/The-Art-Of-Rifle/dp/1581605927/) to learn how to wield it effectively.