Meanwhile, a nonpartisan analysis says the Senate bill favors high-income earners.

WASHINGTON — President Trump on Monday promised a tax overhaul by Christmas, even as a nonpartisan tax analysis group said the Senate package would leave half of taxpayers facing higher levies by 2027.

Speaking before a Cabinet meeting, Trump said, “We’re going to give the American people a huge tax cut for Christmas – hopefully that will be a great, big, beautiful Christmas present.”

Trump spoke as the Tax Policy Center said that while all income groups would see tax reductions, on average, under the Senate bill in 2019, 9 percent of taxpayers would pay higher taxes that year than under current law. By 2027, that proportion would grow to 50 percent, largely because the legislation’s personal tax cuts expire in 2026, which Republicans did to curb budget deficits the bill would create.

The policy center, a joint operation of the liberal-leaning Urban Institute and Brookings Institution, found that low-earners would generally get smaller tax breaks than higher-income people.

In 2019, those making less than $25,000 would get an average $50 tax reduction, or 0.3 percent of their after-tax income. Middle-income earners would get average cuts of $850, while people making at least $746,000 would get average cuts of $34,000, or 2.2 percent of income.

The center also said the Senate proposal would generate enough economic growth to produce additional revenue of $169 billion over a decade. That’s far short of closing the near $1.5 trillion in red ink that Congress’ nonpartisan Joint Committee on Taxation has estimated the bill would produce over that period.

The top Democrat on the Senate Finance panel, Sen. Ron Wyden of Oregon, said the study showed that “middle-class Americans will ultimately see a tax hike under Republicans’ plan while corporate sponsors line their own pockets with multi-trillion-dollar giveaways.”

Antonia Ferrier, spokeswoman for Senate Minority Leader Mitch McConnell, R-Ky., cited a separate study by the Tax Foundation. That conservative-leaning group has said the Senate bill would produce higher wages, nearly 1 million new jobs and enough economic growth to generate nearly $1.3 trillion in federal revenue.

The Senate bill would repeal a requirement that Americans have health insurance or pay a fine. The provision is not in the version of the tax overhaul passed last week by the House.

Striking the health care provision might satisfy some Republican moderates who oppose repealing the language, but would also blow a hole in the senators’ tax cut plan, leaving them $338 billion short of their revenue goal over the next 10 years.

Moderate Republican Sen. Susan Collins of Maine, whose vote the White House needs, said Sunday the tax advantage some middle-income consumers would reap under the tax bill could be wiped out by repealing the mandate under the Affordable Care Act.