Cutting the income tax in half will make it grow back faster.
Let me be specific. The Income tax without apportionment was made legal in 1913 after 52 years and was originally a flat tax. But the 16th Amendment was a de facto business permit for certain lobbyists to trade tax favors inside revolving doors with Treasury and Congress.
Since 1913 there have been FIVE MAJOR tax reforms of the Income tax code. Each made the income tax flatter and simpler. But each time the tax code was back to insanity within 15 to 20 years.
Since the last major reform in 1986 under President Ronald Reagan, there have been more than 18,000 amendments to the tax code and once again we are back to insanity.
The Income Tax code is a cancer. The 16th amendment is the root of the cancer.
Cutting the cancer in two will result in cancer coming back with a vengeance.
The only way to kill this cancer is to repeal the 16th amendment and pass a replacement tax code.
SCOTUS has correctly ruled that the only effect of the 16th Amendment was to define the income tax as not being a "direct tax," which necessarily means that it is an indirect tax, and so is subject to the Constitutional constraints on indirect taxes.
Unfortunately, SCOTUS has incorrectly interpreted the semantics of the uniformity requirement. But the requirement clearly and unambiguously requires that the tax itself, not the law that imposes it, must be "uniform." Progressive rates violate that constraint.