Earlier quoted context omitted.
Surely if there was a revolution, the other parts of the territory could simply ignore Brasília?
Yeah, this is the part of the argument I don't understand... why do you need to control the government buildings? Just declare new ones. It's the guns that you need to control to own a country.
Many revolutions that worked, worked because the people in the capital physically wrested control, power is a funny thing, many people that have real power (example: the army soldiers, that actually have the guns with them), prefer the status quo unless it is very clear something changed (example, the soldiers might obey some rebels if the rebels kill and replace part of the chain of command).