This is a short story written prior to 1985, and I think included in an anthology or SS collection. It is written as a first-person letter to a congressman, complaining about deplorable social conditions, and advocating a wholesale move away from conspicuous consumption. Those who refuse to walk away from their wealth will be targeted by the revolutionary activists. It ends with a line something like, "So, here's looking at you, Senator, right down the barrel of a rifle." The setting is a dystopian near-future. While I have it filed in my head as SF, since it's been about 35 years since I read it, I don't remember any other details.
Thanks to a suggestion from Alan, I found it in Omni.
Dear Senator, I'm writing to you because you are our senior Senator and because you said at election time last year that you were our servant and that we should write to you immediately if we had any grievances. You were very definite, and you even got a little huffy and said it was actually a citizen's duty to write to his Senator and let him know what was going on. Well, Senator, I thought about that a lot. Naturally, I didn't believe the part about you being our servant, what with you earning 50 times or 100 times, or for all I know 1000 times what we do. But the thing about writing to you, which you were so insistent on, that part got to me.
[. . . .]
"Well, I don't know," Grandfather said.
But the salesman knew. It took him about fifteen minutes to sell the lopsided body to my grandfather.
You get a one-month guarantee on retreads. My grandfather got into it the following day and it lasted him three weeks. Then the heart began to race and flutter, one kidney shut down completely, and the other three only worked part-time. A lung patch blew out, the intestines started leaking, and the liver began to shrink.
Grandfather is in bed now, and Doc Saunders says it's a day-to-day thing. The company won't make good on the body. They got some pretty nifty clauses in that contract of theirs, and our block legal advisor says we could fight it in the courts for ten years and not be sure of the outcome. And in the meantime Grandfather would be dead.
[. . . .]
Remember—there's a hell of a lot more of us than there are of you. We've never been able to bring this thing off before, my grandfather tells me—never in the history of the world. But what the hell, there's got to be a first time for everything. Maybe we'll even make it this time; pull down your Golden Age and build our own.
I don't expect you'll see it our way. So here's looking at you, Senator—right down the sights of a gun.