Well the American Corruption tends to feed into people who can afford to pay for the corrupt system... Basically rich people and businesses...
Okay but the examples here are politicians doing what they campaigned to do and were elected to do. It feels like people are refusing to consider any evidence to the contrary. Sure sometimes politicians do sell out. But if you say that they always sell out AFTER being presented with evidence that is not true you are simply ignoring the facts. I presented a source that backed up my assertion. You have presented jack shit and yet you continue to insist that my assertion is completely wrong.
In my view the "corruption" or "selling out" of politicians is only tangentially related to whether they keep their promises, but I can't speak for the previous people in this argument (i.e. I'm not "moving their goalposts"). I think you're right, the popular perception that politicians are liars willing to say anything to get elected is false, but I still think the system is corrupt.
Since campaigning has gotten so expensive, with the costs of creating an organization on the ground and the influence of advertising, it seems like candidates are effectively screened by their ability to raise a competitive amount of money. If candidates rely on many small donations then this expensive campaigning system isn't necessarily corrupt (though is still pretty dysfunctional in my opinion), but for most major candidates that rely on super PACs to alleviate their advertising costs, that candidate's ability to compete and media coverage is contingent on conforming to the views of at least some members of the mega-rich stratum. There are billionaires that support the democrats just as there are billionaires that support the republicans, but they're still getting a disproportionate amount of influence, and it's one of the many factors that makes the barrier of entry for a new third party even higher (even if the system stabilizes to two parties again, these barriers allow the existing parties to entrench themselves in the face of unpopularity).
For smaller congressional campaigns and the like, the party influence is much greater, since they (and their backers) will be the chief source of funding. This isn't necessarily unethical, obviously a party should be able to support its candidates, but it further stifles independent or third party candidates from getting seats in the legislature, something that I think would be a much more realistic route to reforming the fundamental structure that creates these problems than say, just a Sanders presidency.
This isn't Chinese Hong Kong levels of "these are your state-approved options, enjoy your democracy", and candidates like Sanders (and Trump I guess) have shown it is possible to shake things up, but people's feelings of being disenfranchised by the rich aren't unfounded. If a person doesn't like the democrats or republicans, their options are greatly constrained, and the rich are a part of keeping it that way.
Of course, it's worth noting that Hillary has gotten a large portion of campaign money from small donations, and has promised significant campaign finance reform, so many of the claims that she represents part of this system's worst failings are false. But it would be my speculation that the democrat's strategy of reform is motivated more by the prospect of damaging and maybe finally eliminating the republicans than any selflessness (with Sanders' success pushing the issue forward in importance). For what it's worth, it's really the republicans who are corruption incarnate when it comes to this, even if the democrats do happily continue to use and abuse super PACs and the like.