I totally agree the legalized corruption in the US is causing huge problems, and preventing the fixes I mentioned above (higher taxes for the rich and for companies, closing loopholes, etc).

If you live in the US, I'd encourage supporting Represent.US, an anti-corruption / good-governance group. There is a critical anti-corruption, pro-democracy bill that they support nearing the floor of the senate now, and they need more people to make calls to voters.