I don’t think you can just call capitalism corporatism when it does things you don’t like. Capitalism wouldn’t exist without the concentration of violence the state monopolizes to suppress resistance and dissent, and the retention of their system. Capital and the state are intrinsically tied.
Anarcho-capitalists are decidedly unserious people. Murray Rothbard, when asked where the homeless would reside in his society, responded, “who cares?”. Anarcho-capitalism is an oxymoron anyway, as anarchism stands against hierarchical organization, the negation of direct democracy and the institution of private property — at least in the hands of the capitalists.
Consider the U.S. government and its founding. It was founded by liberals who wanted government to be limited to only providing protection of the people and defending their inalienable rights, anything more was regarded as tyranny. They even tried to retain the right of the people to alter or abolish their government. Now we live in the largest imperialist state in history, with militarized police and surveillance everywhere domestic and abroad. We have the largest prison population per capita of any country. This government is never going to be abolished unless there is revolution. Liberal democracy is a fallacy, and there is no retention of limited government in practice. Only anarchism can abolish the relation of exploiter and exploited.
The centralization of power has happened gradually and I don’t think can be attributed solely to the “Progressive Era”. You’re probably bitter that Roosevelt signed the NLRA and cry that’s too much overstep. I think our modern authoritarian government is the product of shifting from dual federalism, and seizing the opportunity to build a greater surveillance apparatus after 9/11. Plus, cooperation with cronies in the neoliberal era (late 70s to present).
You are flat out wrong. What we have now is not caused by Marxists. There are no Marxists in our government at all. Each president since Carter has advanced a neoliberal agenda, that which is more in line with your desired “free” market, cutting corporate tax rates, crippling public unions, expanding global trade, austerity measures (especially state governments), cutting corporate regulations and allowing for greater corporate impunity on the world stage (look at the MTA that was proposed under Clinton).
Now you’re just entertaining deluded conspiracy theories. Seek help.