Try reading "The State and Revolution". It explains why democracy and capitalism are antagonistic forces. A 2014 landmark study showed that a basic assumption of the book, that the rich basically determine policy in a liberal democracy, is essentially correct in America. Unfortunately, the rich cannot be tamed under capitalism because they can perform a coordinated capital strike that brings the economy, and the regulatory system, to its knees. This is the private power that they have.
Not sure what your comment is in reference to; however, I'm perfectly capable of interpreting current events for myself without relying on meta-analyses that only serve to confirm what I already know. Namely, that money as a corrupting influence in our politics is a growing specter that undermines peoples' ability to react appropriately in an increasingly complex world. The 'capital strike' you refer to sounds highly theoretical, save for the fact that the world's elites have found greater boldness in their ability to irreversibly extract value from the economies that have made them wealthy and move it elsewhere. Indeed, this doesn't bode well for our society, but the US is still a pretty nice place to reside and do business, comparatively. I, for one, believe that the ideal of this place as a beacon of hope for the common man can be restored, but it could go a different way too.
The wealthy wield power for much more mundane reasons. They tend to be politicians, friends with politicians, for much more face time with politicians, and pay for lobbyists.
