Earlier quoted context omitted.
Not unique to the U.S., and also is called corruption or cronyism in general terms when money mostly enables one to “effect systemic change”. The U.S. civil rights protests stand in stark contrast as one example, at least.
People only call it corruption when they disagree with it. When they agree with using money to solve problems it's called charity.
Hmm, I am not sure. If you look at different examples of corruption vs. charity, a defining characteristic of corruption (I think) is that it benefits a small and select group of organizations or people who would have been find even if they had not received that benefit. OTOH charity is usually beneficiary-blind, absent any criteria for being a recipient, e.g. being afflicted with a disease, or coming from economically disadvantaged backgrounds etc. Secondly, organizations or people who receive charity do not experience an increase in power or influence upon the receipt of a benefit, which is usually the case in receiving a benefit under corrupt circumstances. But it really all depends, and there are of course overlapping scenarios. It just means that auditory processes are required, not that one should assume "charity for causes I don't like" = corruption.