Because the procedural mechanism Republicans want to use to pass Trump's policy agenda requires that legislation generally not add to the federal debt, that means Republicans would have to offset the tax cuts with massive amounts of cuts elsewhere in the budget.

And even GOP lawmakers are admitting the cuts they’ll need to make will be painful for the American people.

"It will be littered with a collection of ideas, some of which Americans are going to really not be for, but hey, if we don't sacrifice, if we don't understand that this is going to be a painful process, nothing’s going to change," Republican Rep. Mike Flood of Nebraska said in an interview with Bloomberg on Thursday, referring to the forthcoming GOP budget that will be used to pass Trump's tax-cut agenda.

“My message to the American people is: We as a nation, as Americans, have to recognize that this is such a big problem—our debt—that we’re going to have to say no to some programs that we like but we simply can’t afford,” he added.

Republicans have been circulating proposed cuts, including deeply slashing Medicaid—which insures more than 72 million low-income Americans, or more than 20 percent of the U.S. population.

Also on the list? Axing tax breaks to make child care and higher education more affordable. Major cuts to food stamps. Taxing scholarship money. And curtailing employer transportation benefits that make commuting more affordable.

Of course, pain for the American people would come only if Republicans pass the legislation, which is in doubt.

After meeting behind closed doors for five hours on Thursday, House Republicans still don't have an agreed-upon framework for how to move forward, Politicoreported.

That comes after House Republicans couldn't agree to a framework during a recent three-day retreat.

And even if they do figure out a framework, getting it passed will be a separate story since the draconian cuts necessary to cut taxes for the rich would politically damage GOP lawmakers in swing seats.

Republican Rep. Elise Stefanik of New York is expected to soon be confirmed as United Nations ambassador, meaning that Republicans will then have just 217 seats in the House. In other words, for months, their leadership won’t be able to lose a single House vote if they want this tax bill to pass.