How Big Capitalists Will Subvert a Free Libertarian Society
I actually described how this would work in the story:
In a system with a minimum of checks and balances, beyond enforcing property rights, there is nothing to prevent the wealthy from utilizing their power for political gains.
Keep in mind a libertarian society has no protections against rising inequality. Libertarians do not view inequality as a problem, and thus offer no mechanisms to combat it.
If people operate as rational individuals seeking optimal outcomes for themselves, then their natural inclinations would be to buy politicians through any legal means necessary to push policies benefiting them.
America today has considerable amounts of restrictions on campaign finance but not nearly enough to prevent donors from essentially buying politicians. A liberarian society would even have less such restrictions, because it is against government regulations. It wants to keep them to a minimum. Restrictions on political donations would go against the libertarian ideal that you should be able to spend your money in whatever way you please as long as you don’t coerce other people in some way.
A libertarian society does not initially allow big capitalists to take over the market. What you are not considering is that a libertarians political system is not static. Like any constitutional and representative democracy it can be altered over time. My point is that all political systems will change over time , and they will change in direction of those who hold most power. Money is power and so the wealth will forge the system in their image.
Hence my argument for a more social democratic model where, redistributive mechanisms are in place and there are more restrictions in how money is used politically, to hinder this drift towards crony capitalism.