This makes no sense in an economy where wealthy households have enjoyed the largest pre-tax raises. They are bringing home many more dollars, and each of those dollars is being taxed less than in the past. The middle class and poor are on the unhappy end of both trends.

Obama tried to reverse these broad trends and had some success. The core of his domestic policy, in fact, was fighting inequality. He substantially raised taxes on the rich, while keeping the Bush tax cuts for the middle class and poor. He also expanded health care and other middle-class programs. Before Obama, there were also bipartisan efforts to expand Medicare and low-income tax credits.

But these efforts haven’t been nearly enough to make up for the soaring pre-tax inequality — or even to make the tax code more progressive than it used to be. Middle-income families face a higher rate than a half-century ago: 28.6 percent in 2014, versus 24.8 percent in 1964. The economist Gabriel Zucman notes that the increased taxes on lower-income families have made it harder for them to save and invest. “It’s part of the reason you have such high wealth inequality,” he said.

Now President Trump, Mitch McConnell and Paul Ryan are trying to widen inequality even further. Their tax bill doesn’t touch the payroll-tax rate — again, the single biggest tax that most households pay. The bill does cut income taxes for the middle class, but only modestly and only temporarily. The tax cuts benefiting the wealthy, including cuts to the inheritance tax and the corporate tax, are much larger and permanent.

Researchers at the Tax Policy Center, a vital source of independent analysis on a plan that’s been rushed through Congress, have estimated the long-term effects on each income group. Crucially, their estimates don’t ignore the bill’s impact on the deficit — and thus include the spending cuts that will eventually need to follow. Even if those cuts fall equally on each household (and, in reality, Republican leaders favor cuts that fall disproportionately on the middle class and poor), the tax bill amounts to an enormous effort to increase inequality.