The following linked article is interesting. The comments are interesting as well.
"Tax Cuts: The B.S. and the Facts"
by Larry Beinhart. The Smirking Chimp. November 12, 2008.
My take is that it's how the tax revenue is spent and not just how high or low the margin rates are that matters most in a mundane, mixed economy. Throwing money at the military is throwing it away relative to investing the same amount in what will return on the investment over and over and over such as the following: Higher education; solid, green infrastructure; and clean, renewable energy (returns through better all-around health and more).
Unless plunder is profit, throwing money at the military is throwing it away. Unfortunately, the U.S. might try more wars for plunder. I've written about that before.