The tricky part, I think is to know whether we're in the first part or the second part of the tax-rate axis. It also shows that we cannot have very low tax rates either.
There are 2 components to the equation. Income and tax rate. Our side believes in increasing the revenue by clearing the path for people to earn more. The other side would rather increase the rate to increase revenue and also use the rate to punish those who earn "too much". We must understand that the curve is dynamic, not static. The lower the tax rate, the more income can be produced by tax payers. I support the philosophy that takes the rate as close to 0% as it can go. Not the other direction.