As Rome transitioned from the Republic to the Empire, the politics could be ruthless. Factions were polarized on everything from tax policy to sports teams. While every one thinks of the gladiatorial expositions as the epitome of Roman sports but the real action was the chariot races. Think NASCAR on tow wheels and all four horses out in front. The races were classed by teams and the teams were called by color.
Those who followed Anthony, or Pompe Magus, or Crassis would claim that color and cheer those racers. The drivers were minor celebrities who commanded their own following. This ran right down to the street gangs. Pick a color and stick to it. If you keep up you get called for the real fun. Rioting. If Crassis put out the word, he could command a riot in just a couple hours and shut down that part of the city.
Is your political opponent going out to speak? I hope he brought his boys because our guys might show up and have their own say. Gangs blocking Senators from entering the Forum was a serious problem. Worse, it became accepted.
Over running the Forum with your gangs was not done. Some lines can not be crossed. A very non-metaphorical Rubicon. Every hand would turn against anyone so foolish and irresponsible.
It seems Mr Trump tried to cross that river but now finds himself mired in the muddy middle with the current washing away everything he brought with him. I will have no sympathy for those still clinging to his colors.
“… and you can tell Crassis that the next time he tries to run his charioteers in to the forum, they will not meet the City Guard waving clubs. Equestriat will bring steel to ensure there will not be any further demonstrations.”