(a) money
(b) popular revolt (or vigilance)
Without (b) there's just (a).
"Yeah, I'm getting these paybacks from companies, but I do it to support my campaign, else this scoundrel, my opponent would have gotten elected, who would have voted for very bad policies".
Besides, long term, the system self-selects against too much morality. If they can't trust you to keep your mouth shut and play the game, you wont get the support you need to get to the next level.
The one willing to put up with everything and anything, either participating, or keeping their mouth shut and pretending to be above it while still allowing it to happen, becomes President.
* The FED
He who has the money controls the FED too.
There's no capitalism without government, that would be anarchy.
Whether it's big government (with welfare, education, etc) or not, is another thing. But capitalism, pure or not, requires police, army, courts, and so on, and by extension, a tax system to fund their operation.
Else, it's just might that enforces anything it wants, and there are no contracts other than between people of equal power (since the more powerful can just steal whatever people with less power have).
Of course these terms were redefined a lot during the last 100 years. We might simply misunderstand each other because each of us uses a different definition made by another person and taught by another school of thought as well as different university/professor.
Anyways even if there was a government and law enforcement etc, in pure capitalism having more money would not help, government would be strictly neutral and the civil law minimal. If the government helps a company it's definitely not pure capitalism regardless of what the exact definition is.
Doesn't make sense to have private courts since anybody with a large enough power (e.g. hired thugs) can take them over.
If you mean that the individuals in such a scheme would agree to pay each to have a "private court/police" enforce their contracts etc, then that's the same as government, just one without voting (and presumably there would be some way to settle how those courts/police would operate too, which might end up as a contract itself, but people will have to agree to its terms first, so there's some voting there too).
>If the government helps a company it's definitely not pure capitalism regardless of what the exact definition is.
How that makes it anything more than wishful thinking though? If the government officials pocket money to favor one company, that's fully compatible with the greed and egoism that's essential for capitalism (according to Adam Smith and co “It is not from the benevolence of the butcher, the brewer, or the baker that we expect our dinner, but from their regard to their own interest").
What would prevent them to do it under the table, aside from morals?
Actually, there is voting. Those individuals are voting with their money. But, this is more direct market signaling rather than being relayed to a "representative" in our "republic".
In that case, a person with more money will have more influence over that police/court etc to favor them.
How's that different (except cruder) than the current scheme, where the do it through influencing government first? It just makes it more explicit and removes any counter-balances.
I reiterate my recommendation of Ludwig von Mises. His books are really good and it's worth a read even if you completely disagree (just like I read Marx). He tried to answer every question you've written here and definitely more in detail and better than I ever could. There are even individual texts online (taken out of his books) where you can read about a single issue - the texts are not even that long, 20 minutes a piece.
As for that though:
>You're thinking about it on a too small scale, but there are many more factors - it's not just a single transaction! Consider what happens to stocks when a company does something unpopular.
Their success might not depend on popular demand or any stock market. They might have control over something valuable like oil or water supplies, which is not very elastic in its demand.
Then there is the people factor - people are not dumb, they simply will not sell their water/oil resources if they see someone trying to build a monopoly.
IMHO oil company influence on the government is a major hold up of electrification (actively opposing nuclear power plants and so on) - without that influence electricity could be much cheaper and electric vehicles in bigger demand, government funds could be invested in research of batteries etc.
The assumption of modern anarchists is that contrary to the past, a single individual today is very powerful and independent thanks to technology and the riches it comes with - and they could use that strength in combination with other individuals to resist corporations and shape the world around them. Consider that just 100 years ago mere communication between ordinary people was almost impossible on longer distances, today ordinary people are able to buy a tank or a small fighter jet (of course in a group - BTW I actually have a friend that owns a tank and another friend that owns a fighter jet, of course gunless).