So I read this short story a few years back in an anthology I found in a university library. The anthology was titled "Best American Sci-fi" or "Greatest Works of Science Fiction" or something along those lines. I think the story was from the 70s but I have no idea who the author was or what the title is.
It was pretty short. The main character is a man who has a large assistant/bodyguard with him. The man gets out of a van, unloads a wheelchair, and then talks about how he's nervous about the situation. He talks for a bit about he modified the chair in order to protect himself. I don't remember it being in first person but you could hear the main character's thoughts.
The main character then injects himself with a blue liquid. He slumps in the chair and loses most of his motor functions but his senses and processing skills become extremely powerful. The main character and his bodyguard then go around this normal suburban neighborhood, which has been explained as under the control of this corrupt congressman.
The story doesn't really explain what the congressman does other than use a new field of science to manipulate his constituents. I don't remember what it's called, but the main character is also using it. The field is what developed the drug he's using and it's also how he deters people from attacking him--it has to do with a lot of psychology.
The main character continues driving around this neighborhood, analyzing people, until they start to get suspicious. A crowd gathers around him and threatens to hurt him, so he releases a scent-bomb that messes with the psyche of all of the people around him. I think the bodyguard gets knifed or killed.
The story ends with him loading back into the van, thinking about the corrupt congressman and how he almost died. The drug wears off and he's a normal human again.