This is precisely what I am talking about, though - "the rich dismantling democratic mechanisms" *is* the phenomenon I am describing, and it is a pretty much unavoidable outcome with the social and political dynamics that capitalism introduces as an ideology (which is what it is - not just an 'economic system' as it's often portrayed).
Very bluntly speaking, the core ideological tenet of capitalism *is* wealth accumulation, and the remaining way to do that once all the low-hanging fruit is exhausted, is to capture structures of power to your own (semi-)exclusive benefit. And since wealth accumulation is ideologically a virtue in capitalism, this can easily end up overriding 'democratic mechanisms' in the arena of public discourse. If you convince people that chasing wealth is good, then they will (sufficiently) approve of regulatory changes that function to that end, and more generally support the wealthy.
To stop this from happening, you'd have to remove the concept that "increasing wealth" is a desirable thing and a virtue, and by that point you're not talking about capitalism anymore, because that is what defines it. So the only way to have reliably regulated capitalism is to *not* have it at all.
