> 4. Corporate tax receipts have been steadily falling as a percentage of GDP. [3] Why shouldn't corporations (that benefit from a healthy and educated workforce, a safe and secure environment, a working transportation system, etc.) be paying their fair share to keep the national debt in check?

I'd be incredibly careful assuming that lower tax receipt from corporate income is due to lower tax rates.

Why? Because lots of things impact corporate tax receipts beyond tax rate.

If you look at the graph since 1980, you can clearly see a correlation with economic downturns. In fact, they tend to lead downturns which makes sense as corporations see a drop in profits as the economy slows and heads into recession.

Corporate tax receipts would also drop as corporate investment increases. When Amazon spent billions on expanding their business, profits dropped and so did tax receipts.