This also sounds like chapter 17 of Ron Goulart's "When The Waker Sleeps," but only vaguely.

My apologies for not expanding on this yesterday morning, but I work second shift and it was already getting late. Otherwise, I would have kept on reading to chapter 21:

"Hurray for the President!" shouted nearly a hundred voices.
"Which President is this?"
The girl replied, "Should be the President of the fourth floor. Each floor has its own."

The President then makes a speech and bangs on a ceremonial piñata, which explodes, clay shrapnel knocking him down. Instead of another floor being blamed for the bomb, suspicions fall on our hapless "waker," suspected of being a member of the USAUSA (United States of America Underground Secret Army, sort of an ultra-CIA). While he's in custody he succumbs to the need for a "nap," and the next chapter is sort of an epilogue that closes the book.
Chapter 17 is the one that begins that particular timetrack. It takes place in a similarly manic "Brasil2".