How can a tiny faction play a role in approval ratings?

How can a tiny, insignificant group with zero influence—one that shouldn't even be given a second thought—affect the President's declining approval ratings?
Even if they did something, wouldn't a 1–2% impact be a lot?
But how is Jae-myung's approval rating plummeting to 30% right now?
Regardless of that tiny faction, isn't the approval rating tanking simply because Jae-myung is being an incompetent idiot? ㅇㅅㅇ