The "one of their own supporters" whom the Clodian mob reportedly planned to execute on the spot was Numerius Quintius Rufus, a populist tribune of the plebs who was actually allied with Clodius’s faction.

In Section 79 of Pro Sestio, Cicero lays bare this specific conspiracy to show the judges the cutthroat nature of Clodius’s urban gangs.

The Setup for the False Flag Operation

Cicero explains that the mob had calculated that if Publius Sestius died, the public outrage (odium) against Clodius's faction would be severe enough to destroy them politically. To protect themselves, they concocted a backup plan:

1. The Sacrifice: They intended to slaughter Numerius Quintius Rufus right there in the Forum.
2. The Framing: Because Numerius was a well-known, public supporter of Clodius, his death would allow them to claim that Sestius's aristocratic faction had initiated the day's violence and slaughtered a tribune of the people. [1]
3. The Legal Alibi: This fabricated "equal body count" would give them the legal cover to claim they only attacked Sestius in an act of mutual street warfare, rather than staging an unprovoked political assassination.

Why Numerius Survived

Cicero notes that Numerius was terrifyingly close to being murdered by his own allies. The mob had already dragged him down to the Rostra and were preparing to kill him when the news broke that Sestius was still breathing.

Once the mob realized Sestius had survived and was being carried away alive, the plan collapsed. Killing Numerius would no longer serve as a useful counterweight to a dead Sestius; instead, it would just mean they had murdered their own ally for nothing. Realizing the plot was ruined, the thugs dropped Numerius, and he fled into the night to hide. Cicero sarcastically points out that Numerius owed his life entirely to the fact that Sestius didn't die. [1]

If you want to dive deeper into the chaos of the late Roman Republic, we can explore:

• The role of Numerius Quintius Rufus as an obstructionist tribune.
• How Clodius’s gangs operated like an organized crime syndicate in the Roman Forum.
• Other instances of false flag operations or political framing during this era.