Trump and others have pitched the plan as a middle-class tax cut—and it would aid lower- and middle-class families by cutting individual tax rates and doubling the standard deduction.

Estate Tax

But it also calls for eliminating the estate tax, which currently applies only to estates valued at more than $5.49 million for singles or $10.98 million for married couples. And it would repeal a 3.8 percent net investment income tax that applies to individuals with incomes above $200,000 a year. Cutting the top individual tax rate and setting the top rate for partnerships and other so-called “pass-through” businesses would also benefit high-income taxpayers. Mnuchin said the White House aims to offset any reduction in high earners’ tax rates by “significant reduction of deductions.”

“If the president’s plan is to give a massive tax break to the very wealthy in this country—a plan that will mostly benefit people and businesses like President Trump’s—that won’t pass muster with we Democrats,” Schumer said Wednesday morning on the Senate floor.

Without Democratic help, Republicans would have to seek a simple-majority vote on the eventual legislation—a procedure that would prevent any of the measure’s provisions from adding to the deficit outside the normal 10-year federal-budgeting window. Economists have said the sorts of cuts Trump wants would do just that. If so, the cuts would have to be set to expire—perhaps within three years, based on a finding by the congressional Joint Committee on Taxation.

‘An Underperformance’

Settling for temporary tax cuts instead of lasting changes would be “an underperformance” from House Republicans, said Peter Roskam, an Illinois Republican and member of the tax-writing House Ways and Means Committee. Senate Majority Whip John Cornyn, a Texas Republican, was cautious in his remarks.

“I like low tax rates, but I don’t know how we pay for it,” he said. “That’s the question—and what the other provisions are going to be.”

The plan that Mnuchin and Cohn unveiled Wednesday does allude to one major revenue-raiser: It would scrap the federal-income tax deduction that individuals can claim for the state and local taxes they’ve paid. Repealing that deduction would be worth as much as $1.3 trillion over the next decade, based on an analysis by the Urban-Brookings Tax Policy Center, a Washington policy group.

The deduction mostly benefits high earners in high-tax states that tend to vote Democratic; the largest beneficiaries are California, New York and New Jersey—all relatively high-tax “blue” states. Conservatives favor eliminating the deduction, which they’ve called a federal subsidy for high taxes at the state and local levels.