The “Prince of Darkness,” a.k.a. Bob Novak, the late columnist, once opined that: “God put the Republican Party on earth to cut taxes. If they don't do that, they have no useful function.” Pat Buchanan, another “right-wing” columnist, took issue with Novak’s view of the GOP in “Why God Created the GOP” and opined that “to be historically precise, the GOP was not put here to cut taxes. From infancy in the 1850s, its mission was to halt the spread of slavery.”

Buchanan then launched into an elegant little history of taxes under Republicans from 1865 to 2012 that, given the current push to cut income taxes, is quite worth reading. The article pretty much refutes Novak’s claim. Maybe Novak was just being overly broad, “talking big” to make a point. In any event, I miss old Bob; he was an old-school gentleman, despite being the Prince of Darkness and all.

One can understand why Mr. Novak might have had such a reductive opinion of the GOP, as he began his career in journalism in the 1950s, when the personal income tax had a top marginal rate of 91 percent. During Novak’s life, the top rate ranged from 94 to 28 percent. But how would such different rates affect revenue? Did the IRS reap three times the revenue when the top rate was three times higher? In “The Good Ol' Days: When Tax Rates Were 90 Percent” at the Mises Institute, Andrew Syrios provides an answer:

It should be noteworthy that back in the 1950s, the government wasn’t actually collecting any more in tax revenue as a percentage of GDP. There’s something called Hauser’s Law, which basically states there is a maximum threshold on how much the government can tax out of its population. I think this “law” is no such thing. If the government really wanted to expropriate more, it could do so. But Hauser’s Law based on the fact that in pretty much every year since 1950, the government has collected between 17 to 20 percent of GDP in taxes. […] tax receipts from personal income taxes have consistently been between 7 and 9 percent (as a % of GDP). In 2014, they were 8.1 percent.

Syrios then provides a chart (the third one) that drives his point home, and what you see is a fairly flat line for personal income tax receipts while the line for the top marginal rate is all over the place. One might infer from the Syrios chart that lowering the top statutory tax rates doesn’t seem to affect tax revenue much. So surely there were other factors that account for personal income tax revenue being so steady since 1950. What were those other factors?

One of the other factors might be what all the other tax rates were. Since the top rate was so ungodly high, maybe all the other rates were quite low. But income earners not affected by the top marginal rates often had their own high tax rates. Since the Syrios chart starts at 1950, let’s go to the 1950 1040 form and look at the Tax Table on its last page. This table was for earners with incomes of less than $5,000. If one had an income one cent below $5K, wasn’t married, and couldn’t itemize one’s deductions, then one’s tax liability was $724, which gave one an effective rate of 14.48 percent.

That rate is higher than the average effective rate of the bottom 90 percent today (see this chart). Even so, $5K was decent dough back in 1950. But an income of $2,500 could have gotten one a tax bill of $289; an effective rate of 11.56 percent and also higher than the average of about the bottom 90 percent today. One had to use the 1950 1040 instruction booklet if one’s income were more than $5K, and the Tax Rate Schedule on its last page is instructive: everyone was getting hit with high tax rates back in 1950, not just those hit with the top marginal rate.

If more income earners in mid-20th Century America, even working stiffs with modest incomes, were actually paying income taxes and at much higher tax rates than today, then what accounts for the flat line on the Syrios chart? Maybe GDP was measured differently back then. Maybe the data and numbers from that era can’t be trusted. Maybe Hauser’s Law “is no such thing.”

Nowadays we have entire quintiles of income earners that have average effective income tax rates that are negative, while fully half of the revenue from the personal income tax is now provided by less than 5 percent of income earners. So if the flat line that illustrates Hauser’s Law is true, then the explanation may be that the percentage of “rich” Americans has been steadily growing since 1950, and that they’ve been making up for the revenue shortfall from the bottom half of income tax filers. Regardless of whether there are proportionately more individuals who are “rich” than in 1950, it’s true that the personal income tax burden has been falling on fewer and fewer shoulders.

Because of the tricky situation we’re in today with the Federal Reserve reversing policies and trillions in federal debt coming due and needing to be repaid, caution is needed. Changes to tax rates need to be phased in, incremental, gradual.

Contrast the Federal Reserve’s gradualism in raising its funds rate with how Congress wants to cut tax rates. After the funds rate rose by 0.25 percent in December 2015, it took another year to rise by another such increment. But Congress wants big tax rate cuts, and right now. And they want to slash income tax rates for folks who barely pay income taxes. The middle quintile’s average effective income tax rate has not been above 3.8 percent since 2000. High personal income tax rates are not why the middle class is shrinking.

The more important rate cut is for the corporate income tax, and Congress wants to cut it from 35 to 15 percent. That 15 percent target has been revised upward to 20 percent, but that’s still too low. A new 30 percent corporate rate coupled with a pledge to gradually lower the rate further is a more prudent way to go. And I write that as someone who thinks the corporate rate should be quite low, maybe even zero, but we should get there gradually. The Senate plan called for postponing the corporate rate cut until 2019; why not begin phasing it in next month?

Prudent gradualists should be more afraid of a bad tax bill than of no tax bill. If congressional Republicans don’t get their act together soon, they’re apt to be meeting the real Prince of Darkness in the elections to come.

Jon N. Hall of Ultracon Opinion is a programmer/analyst from Kansas City.