Senator Hawley is warning Republican colleagues of a potentially “politically suicidal” decision to cut Medicaid as they move forward with President Trump’s “one big beautiful bill.” Just on Sunday, an analysis of the House GOP’s legislation found that more than 13 million Americans would lose health insurance if it passes. 

Mr. Hawley and a small band of other MAGA populists have been ardently defending the Medicaid program. It has become the major focus of Republican lawmakers who are looking to appease deficit hawks so that they can pass a $4 trillion tax bill. 

In an opinion piece for the New York Times on Monday, Mr. Hawley said it would be morally wrong to kick millions of Americans — many of whom voted for Mr. Trump — off their government assistance. 

“A noisy contingent of corporatist Republicans — call it the party’s Wall Street wing — is urging Congress to ignore all that and get back to the old-time religion: corporate giveaways, preferences for capital and deep cuts to social insurance,” Mr. Hawley writes. 

“This wing of the party wants Republicans to build our big, beautiful bill around slashing health insurance for the working poor. But that argument is both morally wrong and politically suicidal,” he adds. 

Mr. Hawley says his home state of Missouri — which overwhelmingly voted for Mr. Trump in the last three presidential elections — would be hit especially hard by any Medicaid cuts, considering there are more than a million Missourians who rely on the program, not to mention the community health centers and rural hospitals that would close if not for Medicaid dollars.

“Republicans need to open their eyes: Our voters support social insurance programs. More than that, our voters depend on those programs,” the senator writes. “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.”

Other lawmakers have also raised concerns about the future of the Medicaid insurance program, threatening to derail Mr. Trump’s legislative agenda, which will soon be rolled into one gargantuan bill. Senators Murkowski, Collins, and Moran have all said it is a vital program that must be protected. Ms. Collins — the powerful chairwoman of the Appropriations Committee — went so far as to vote against the budget framework itself in April. 

House Republican leadership is moving forward despite those objections, hoping that the Senate will simply eat whatever the House sends it. With only a three-seat majority in the lower chamber, Speaker Johnson will likely argue that their bill must be the one and only solution after he’s able to get everyone on board. 

On Sunday night, the chairman of the Energy and Commerce Committee, Congressman Brett Guthrie, released the initial text of his bill that will be included in the final legislative package. His committee oversees everything from telecommunications to healthcare to energy production, meaning it could be one of the most complex puzzles to solve this week. 

His committee is meeting on Tuesday to begin the process of amending and passing the bill. 

The text that Mr. Guthrie put out on Sunday suggests a deep cut to the current Medicaid program. According to an analysis of the bill by the Congressional Budget Office, instituting new work requirements and allowing certain tax credits to expire will force more than 13 million Americans off of their government insurance. 

That cut to the Medicaid budget would save only $715 billion, according to the CBO estimate, which is miles away from the $2 trillion in cuts over the next decade that conservatives are demanding. 

The House’s deficit hawks are also balking at Mr. Hawley’s and others’ demands Medicaid be protected, saying that all able-bodied individuals must get off the insurance program and get to work. 

On Monday, a trio of House lawmakers — Congressmen Chip Roy, Andy Harris, and Eric Burlison — said the alternative to cutting Medicaid is adding at least $20 trillion to the national debt in the coming decades. 

“Medicaid was meant to be a temporary bridge, not a final destination. You want to help your constituents? Give them the proper incentive structure to grow and thrive. Put them on the path to financial stability,” the three congressmen write. 

Those three lawmakers were part of a band of House debt hawks who delayed passage of the Republican budget framework in April, after feeling that the Senate may not honor their demand for $2 trillion in spending reductions. They confirmed at that time that if the cuts are not made in this bill, then they will enthusiastically vote it down.