Russia satisfies its need for the support of a liberal democratic system by having elections. The Roman Empire satisfied its need for the support of the republic system by still having a senate. These procedures don't need to die for them to become irrelevant to the functioning of power.

The US will likely still have elections. The oligarchy will decide the next president through rigged Republican primaries, and then that president will win through a rigged federal election. The Democrats will take their paychecks to play the honorable losers to discredit claims of election fraud, and AI-filtered feeds will try to push people in the same direction.

You over estimate AI and propaganda’s ability to create stability.

I don't know if they would actually create stability, but this is the plan they seem to be executing on, and they certainly expect a lot from AI and propaganda. If it helps, they're also making massive amounts of autonomous drones, which could be weaponized and deployed against their own citizens. (While automated weaponry is a war crime, that only applies when fighting another state. The US is already committing war crimes against its own citizens with tear gas and inhumane prisons).