A coup requires a counterrevolution, not incremental "improvements." None of the suggestions that follow are remotely possible before the 2020 elections, and even then they stand little chance of implementation: not all plutocrats are Republicans. It's nice to dream, though.
First, the corporate tax rate should be reduced to zero. Next, virtually all income, including wages, pass-through income, dividends and capital gains should be taxed on the same progressive scale. Income reinvested in businesses thus would be tax-free, but all income distributed to individuals would be taxable. Interest income, which encourages savings and the loans that finance economic expansion, would be tax-free. Payments to foreign investors, who own a bit more than 20% of the US economy, would be taxed at internationally competitive rates.
All income should be taxed to finance Social Security, Medicare, and Medicaid, and all caps on taxable income should be removed. To make American businesses more competitive with each other, anti-trust laws must be strengthened and vigorously enforced. Vertical as well as horizontal combinations need closer scrutiny.
The devils can be worked out of the details with implementation, but since none of this is likely to happen anyway, I'll just leave the details to the economists.