One thing I am seeing here is an extension of the meaning of political corruption beyond that found in the dictionary. Here is what the Oxford Dictionary writes:
Other dictionaries may include illegal behavior as well in the definition.
Note that the meaning of corruption does not include unequal access to power by the rich, if that unequal access is neither dishonest nor frauduent. Unequal access is an issue separate from corruption. Trying to eliminate corruption when conflating it with unequal access confuses the two issues and makes dealing with either of them harder.
This is abject nonsense. Maybe if you're an Illinois legislator this sort of equivocating makes sense but the average American recognizes that there's something venal/disgusting about what you have termed, in a very neutral way, to be "unequal access". Politicians claim to represent the public and to uphold the public interest; when unequal access is given by politicians to rent-seeking interests, that's dishonest, a violating of norms of decency. This is why politicians are despised.
Dishonesty is when someone like Cory Booker claims that he's voting against drug importations from Canada because of safety concerns. That doesn't convince anyone; we all know why he made that vote. If politicians were honest about the fact that they were rewarding rent-seeking interests, they'd be punished for it; their obfuscation is effective but, simultaneously, is why it is considered to be corrupt.