And how do the corporations originally acquire the power to regulate themselves into monopolies?
I'll concede that much of it has to do with being profitable enough to afford great lawyers and lobbyists to effect change in Washington. But the reason that they get into that game in the first place is because of regulation of their own business sector, and once in that position, they use their regulatory power for the express end of reducing competition, which is the only thing that businesses truly fear.
Here is an example of how it works. I am a linoleum floor manufacturer in the midwest, whose business scope is the entire US. There are about 4 other manufacturers that make linoleum with whom I compete. One day, one of my competitors makes a product using too much of a particular chemical and his floors poison house-pets; someone figures out that it is the floors, and "pop!", a new regulatory body comes into existence to regulate my industry. The first generation of regulators is made up entirely of goody-two-shoes bureaucrats whose mission in life is to stop the big bad corporations from poisoning fluffy, and so they put a few regulations in place to ensure that the manufacturing process is clean and healthy. While they are at it, they also put some specific regulations in place about supply chain, materials, and labor, driving up the cost of making linoleum, and therefore making it more expensive. Fast forward ten years. The first generation of regulators has been mostly replaced by new faces, and now that the poison scare is off the front page, and fluffy is once again safe, the primary interested party in linoleum manufacture regulation is, well, me and my industry. Because of this, we have put many of the second-gen regulators on the payroll, and or, put our own employees into the regulatory body, if possible. By the third generation of regulators, the industry magnates can put any regulations that they want in place, and use this power to stifle competition, artificially keeping linoleum prices high, and ensuring that any linoleum-making startup will have to have enormous capital, just to pay its attorneys to spelunk through the now fifteen books of regulations for its manufacture.
This is what most modern Socialists call unregulated free market capitalism. But it isn't. The fact that we have a political/social climate so willing to regulate industry is, ironically, the reason why industry is so notably ungoverned. The best, in fact, the ONLY way to regulate business is with demand. It isn't pretty, and it isn't proactive, but it is the only thing that works.