The clear winner of yesterday’s debate, Joe the (kinda, sorta) plumber, focused a national debate on the wisdom and fairness of progressive taxation — the idea that those who make more should pay more in taxes. What neither Joe nor anyone else on the political stage seems to recall is that we’ve had this debate before, 100 years ago, and progressive taxation won so soundly that we passed a Constitutional Amendment, the 16th, to let it go forward.

The 16th Amendment was necessary because of a controversial ruling by a reactionary majority of the Supreme Court in Pollock v. Farmers’ Loan & Trust (1895). Pollack used an obscure and opaque Constitutional limitation on “direct taxes” to strike down a federal law which taxed incomes over $4,000 at 2 percent. Incomes under this figure were exempt, making this a rudimentary form of progressive taxation.

Pollack held that this tax on incomes was a direct tax and thus had to be calculated “among the several states . . . according to their numbers.” This effectively meant that any national income tax would have to be regressive, with residents of poorer states paying a higher percentage of their income to the national government than residents of richer states.

The 16th Amendment overruled Pollack, paving the way for our current progressive income tax. As Akhil Amar explains in his aclaimed book “America’s Constitution: A Biography, “both sides in the national income-tax debate understood that [national income] taxes had been, and were likely to be, progressive income taxes — in particular, taxes that targeted the rich. Such taxes openly sought to democratize the economy. This indeed, was the very reason that Pollack’s defenders so disliked these taxes.”

The Amendment passed because both political parties rallied behind it. It was supported by President William Howard Taft, a Republican, when it was proposed in 1912, and by his successor, Woodrow Wilson, a Democrat, during the ratification process in 1913. It also drew considerable support from the words of John McCain’s role model, Theodore Roosevelt, who said this in 1907:

The man of great wealth owes a peculiar obligation to the State, because he derives special advantages from the mere existence of government. Not only should he recognize this obligation in the way he leads his daily life and in the way he earns and spends his money, but it should also be recognized by the way in which he pays for the protection the States gives him.

Joe the plumber may never actually make the $250,000 a year necessary to trigger the increased tax burden Senator Obama is proposing. If he is ever successful enough to do so, he should count his blessings and recall President Roosevelt’s, and our Constitution’s, wise words.