An artificial underclass, the solution to all our problems.
Getting rid of the existing underclass won't be so easy, but you don't actually have to sell it to anyone, in fact selling it to them is exactly what you want to avoid. What you want to do is price them out of a future.
Houses nobody but the wealthy can afford, services and food that only the wealthy can afford. Healthcare and education only the wealthy can afford.
People will start migrating to look for a better life somewhere else. You don't have to reduce their numbers, just brush them under the carpet somewhere out of sight, you might want them again in case there's a future fashion for having real human staff instead of robots.
The only way to sell it to the population to assure each group that they're not actually the target of the current changes and that as long as they continue things will get better. There'll be some rough times along the way but it'll all work out in the end. Jam tomorrow.
Of course wealth is only relative, if there aren't poor people to be richer than, then nobody is rich.