I want to call attention to the fact that the rich pay almost all the income taxes, so the loopholes can't be all that great.

In fact, the "progressive" nature is one thing that makes the current income tax so much more appealing to the average voter than a flat tax.

Ramesh Ponnuru has his own problems with the idea.

The hard truth is that taxes are too damn high because spending is too damn high, and until this sinks into the population, nothing much is going to improve. It's obvious from looking at any inflation-adjusted table of historical revenues and outlays that in the past we had a perfectly functional Federal government that operated on far less money.