We should be clear at the outset that the tax rate mentioned by freshman Rep. Alexandria Ocasio-Cortez (D-N.Y.) in an interview with “60 Minutes” was not a hard-and-fast proposal meant to be voted on in the House over the short term. Asked by interviewer Anderson Cooper what a “fair share” of taxes looked like for wealthier Americans, Ocasio-Cortez offered an example.

“You look at our tax rates back in the ’60s and when you have a progressive tax rate system,” she said. “Your tax rate, you know, let’s say, from zero to $75,000 may be 10 percent or 15 percent, et cetera. But once you get to, like, the tippy tops — on your 10 millionth dollar — sometimes you see tax rates as high as 60 or 70 percent. That doesn’t mean all $10 million are taxed at an extremely high rate, but it means that as you climb up this ladder you should be contributing more.”

That’s a broadly accurate statement: Fifty years ago, the tax rate on the highest bracket of income was indeed over 70 percent. It applied only to income past the first $400,000 or so until 1965, which is presumably what Ocasio-Cortez meant by the “tippy tops.”

(Philip Bump/The Washington Post)

This is an important distinction that has been blurred in the aftermath of Ocasio-Cortez’s comments. If she were proposing that incomes above $10 million be taxed at a rate of 70 percent, she’s not suggesting that those making $10 million or more be taxed at 70 percent for every dollar. As The Washington Post’s Christopher Ingraham noted Monday, everyone would pay the same amount of tax on every dollar of income below that level.

Using tax bracket data from BankRate.com, we can visualize the relationship between income and taxes paid. Below $200,000 or so, there’s some jerkiness to the lines as incomes above a certain point are subject to higher rates.

(Philip Bump/The Washington Post)

But extend that outward as we look at higher and higher income levels, and the line is essentially smooth.

(Philip Bump/The Washington Post)

Because every dollar over the $500,000 mark for a single filer is taxed at 37 percent, and because as more income is added, that first $500,000 makes up a smaller percentage of the total, the amount that’s paid in taxes for the wealthiest Americans ends up being at about 37 percent of income. (Math nerds: Please write this in the form of a limit.) There are tons of caveats and loopholes, as anyone who has ever filled out a tax return can attest, but we’re making a point broadly about how the system works, so these figures will suffice.

Let’s now introduce the figure that has been most talked about from Ocasio-Cortez’s comments: a 70 percent bracket starting at $10 million.

In other words, a shift that looks like this.

(Philip Bump/The Washington Post)

Now notice that until $10 million, the black line representing Ocasio-Cortez’s sort-of proposal and the gray dashed line indicating the status quo are identical. They diverge only after $10 million, resulting in added tax revenue indicated in the shaded green area.

How much could that raise? Our Jeff Stein talked to experts: $720 billion in a decade.

Now, remember, this applies only to people who make $10 million or more in a year and only to their incomes starting at that $10 million mark. Through dollar number 9,999,999, those people are still paying a bit less than 37 percent on their income. The effect of Ocasio-Cortez’s comments would be that wealthier Americans would keep slightly less of their income than they do now, but as they made more money, they’d still be keeping more income, too.

(Philip Bump/The Washington Post)

For all of the hand-wringing over her comments, not all of it sincere, it’s worth remembering that almost no one would be affected by such a change. In 2016, the IRS reported that only about 16,000 tax returns included adjusted incomes of at least $10 million — 0.01 percent of the 150 million returns filed.

(Philip Bump/The Washington Post)

Again, this was not a hard-and-fast policy proposal. If it becomes one, there’s plenty more analysis to be done about the effects and plenty of debate over what percentage to apply at what income level.

It would also result in extensive polling to see how Americans felt about it. But here, too, Ocasio-Cortez might have an advantage. In 2017, the Pew Research Center found that 43 percent of Americans supported raising taxes on wealthier households — where “wealthier” was defined as $250,000 in income or more.