WASHINGTON — House Republicans proposed sweeping tax breaks Monday in President Donald Trump’s big priority bill, tallying at least $4.9 trillion in costs so far, partly paid for with cuts to Medicaid and green energy programs used by millions of Americans.

The House Ways and Means Committee named its package ‘ ‘THE ONE, BIG, BEAUTIFUL BILL” in all capital letters, a nod to Trump himself. It seeks to extend the tax breaks approved during Trump’s first term — and boost the standard deduction, child tax credit and estate tax exemption — while adding new tax breaks on tipped wages, overtime pay, Social Security benefits and auto loans that Trump promised during his campaign for the White House.

There’s also a tripling of the state and local tax deduction, called SALT, from $10,000 up to $30,000 for couples, which certain high-tax state GOP lawmakers from New York and California already rejected as too meager. Private universities would be hit with hefty new tax on their endowments, as much as 21%, as the Trump administration goes after the Ivy League and other campuses. And one unusual provision would terminate the tax-exempt status of groups the State Department says support “terrorists,” which civil society advocates warn is a way to potentially punish those at odds with the Trump administration.

Overall, the package is touching off the biggest political debate over taxes, spending and the nation’s priorities in nearly a decade. Not since 2017 has Congress wrestled with legislation as this, when Republicans approved the Trump tax cuts, but also failed to repeal and replace the Affordable Care Act, or Obamacare. The cost assessments are only preliminary, and expected to soar.

“Republicans need to UNIFY,” Trump posted on social media before departing for a trip abroad to the Middle East.

Trump said when he returns to Washington, “we will work together on any and all outstanding issues, but there shouldn’t be many — The Bill is GREAT. We have no alternative, WE MUST WIN!”

But one key Republican, Sen. Josh Hawley of Missouri, implored his party not to impair Medicaid, arguing that cutting health care to pay for tax breaks is both “morally wrong and politically suicidal.”

“If Republicans want to be a working-class party — if we want to be a majority party — we must ignore calls to cut Medicaid and start delivering on America’s promise for America’s working people,” Hawley wrote in The New York Times.

As Republicans race toward House Speaker Mike Johnson’s Memorial Day deadline to pass Trump’s big bill of tax breaks and spending cuts, they are preparing to flood the zone with round-the-clock public hearings starting Tuesday and stitch the various sections together in what will become a massive package.

The politics ahead are uncertain. The bipartisan Joint Committee on Taxation said Monday that tax breaks would reduce revenue by $4.9 trillion over the decade — and that was before Trump’s new tax breaks were included.

House Republicans have been huddling behind closed doors, working out final provisions in the 389-page tax portion of the package.