That's what happens when you have a two party system but more than two political philosophies. Given that both parties will work tirelessly to prevent a third party from forming I think the level of corruption should be understood to extend _well past_ the White House.
When I was a teenager & college student, it was very instructive to be involved with 3rd party campaigns and see first hand how much the Dems and GOP will link arms with each other to block out 3rd parties. All kinds of dirty tricks to keep them out of televised debates, keep them off ballots, keep them out of people's minds as a real possible alternative.
And it doesn't help that americans are shockingly well trained to recite the talking points they get handed. "A vote for a 3rd party is a wasted vote", "We need to change the mainstream party from within," "If you don't support the DNC now, you won't have A Seat At The Table later", all that old crap.
the two party system is, in my opinion, unlikely to go away without electoral reform to change election at all levels of American government from "winner takes all" to "proportional representation", if Duverger's law is correct.