Republicans in the House celebrated after comfortably passing their tax reform package last week. But the GOP shouldn't get too excited. The Senate must still pass its version, which would have to be reconciled with the House plan. As such, the GOP's whole dream of overhauling the tax code still faces an uphill climb, not least because offsetting their massive tax cuts — which overwhelmingly go to the wealthy — requires killing all sorts of deductions and breaks in the tax code. All those carve-outs are there to help some group of Americans out. No one is ever happy about losing something that benefits them.

Among those groups are America's graduate students, whose lives could be upended by the Republicans' tax plan.

Most PhD students have an arrangement with their university where the cost of tuition is waived in exchange for the student working as a teaching assistant, lab researcher, and so on. The student is also given a modest stipend for living expenses. Under current law, the stipend is taxable income, while the cost of the waived tuition is not. The bill that House Republicans just passed would make the value of the tuition taxable as well.

You could argue that the value of the waived tuition is "income" in the sense that it's traded for labor. But a PhD education isn't exactly a "liquid asset" — you can't just turn your PhD education into cash to pay your tax bill while you're still in school. The hope for at least some PhD students, obviously, is that their degree will result in much higher incomes. But that comes years and years down the road. PhD students would owe this higher tax right now, each year.

PhD tuition is usually pretty expensive. So treating waived tuition as taxable income increases a PhD student's total pot of taxable income — and thus the taxes they owe — by a lot. Most would see their tax bill jump by 300 or 400 percent, according to early estimates.

Take Amanda Coston, a first-year PhD student in Carnegie Melon's machine learning department, who spoke to Wired about her situation. Her tuition is worth $43,000 a year, and her stipend is worth $32,400 a year. Right now she's only taxed on the latter number, so her tax bill is about $2,834. If the waived tuition were taxable too, her tax bill jumps to $10,209. But all of that has to come out of her stipend, since that's her only cash income. So her stipend after tax would fall from $29,566 a year to $22,191.

That's a huge hit. And remember: The stipend pays for all her living expenses that aren't tuition.

"It really changes the calculus on my finances," Coston told Wired. "This suddenly makes a lot of things like rent, car payments, groceries, all that stuff, no longer affordable."

Perhaps Coston is an extreme case. Tuition varies across universities. Indeed, the average graduate tuition at public and private universities as of 2012 was around $16,000 per year. But about 145,000 graduate students around the country would be affected by the change, with experts estimating their annual tax bills would increase $2,000 or more. About 60 percent of those are in science, technology, engineering, or math (STEM) fields. Of that portion, only 10 percent relied on their own money to pay their tuition. So you can imagine how far-reaching the GOP plan's consequences could be.

"You shouldn't have to pay tuition, and your living costs should be covered." That's the advice Claus Wilke, a computational biology professor at the University of Texas at Austin, gives prospective graduate students. "If that cannot be guaranteed, then the PhD program isn't really worth it."

“If this tax law went through then essentially every PhD program in the U.S. would not meet this bar anymore,” Wilke told The Verge.

Of course, students could just go into more debt to pay for PhD programs. But the whole system of debt-financing to pay for college is unsustainable as it is. And even if more debt was a widespread option, that debt has to be paid off with future income. Academic careers generally don't pay that well.

Make no mistake: This change to the tax code could drain universities across the country of the next generation of teachers, researchers, and more.

Now, in some respects this is a niche issue. Only 12 percent of Americans had an advanced degree of any sort — masters or PhD — in 2015. That this aspect of the House GOP bill has taken off as a news story is indicative of the privileged class position Americans with graduate degrees hold in our society. Most people don't have a graduate degree. But the people who participate in our politics and do journalism and work at policy shops and so forth often do.

Universities could just try increasing graduate students' stipends. Right now, they tend to rely on those students as conveniently cheap sources of research labor. That's of a piece with the way higher education has been transformed into a commodity in America, and how universities have become increasingly financially ruthless. Government has pulled out of funding universities directly, we're relying more than ever on credit and debt to pay for tuition, and the costs of that tuition just keep rising into the stratosphere. The House GOP bill would just push graduate education even closer to being available only to the children of high-income families.

Tuition waivers should be defended from taxation. But we should also all take this opportunity to reconsider the entire role of higher education. Maybe it shouldn't be a commodity, to be bought by those who can afford it, or paid for over time out of graduates' career earnings though fancy debt instruments.

Maybe higher education should just be a public good available to all.