The underground is way stronger than we can possibly believe. In order to achieve the overthrow of a national government, the ground work must gradually be laid, and fertilized. When the soil is sufficiently soft seeds must be sown that, when matured, will bring hardship to the citizenry who will then demand their removal.
Useful idiots will be tapped to "protest". They will infiltrate the ranks of those who are genuinely concerned, and will eventually become dominate. "Demonstrations" will become larger and more deadly. Riots and bodily harm as well as the usual property damage will become the norm. The people will demand that order be restored, and it will be--by a totalitarian force that will become permanent.
That force will be Socialism aka Communism re branded as Globalism. The greater good for the greater number.