Groff v. DeJoy, a lawsuit that could potentially revolutionize the balance of power between religious workers and their employers and co-workers, will be heard by the Supreme Court on Tuesday.

It is an agonizing case, in part because it seeks to unravel a very real injustice.

Federal law requires employers to “reasonably accommodate” their workers’ religious beliefs and practices unless doing so would lead to “undue hardship on the conduct of the employer’s business.” Nearly half a century ago in Trans World Airlines v. Hardison (1977), however, the Supreme Court said that an “undue hardship” exists whenever an employer must “bear more than a de minimis cost” when it provides such religious accommodations (the Latin phrase “de minimis” refers to a burden that is so small or trifling as to be unworthy of consideration).

Pretty much no one thinks that this “more than a de minimis cost” rule is correct. Even Americans United for Separation of Church and State — an organization that, as its name suggests, typically argues in favor of less entanglement between the law and religion — filed a brief arguing that “Hardison is wrong in too many ways to withstand scrutiny.”

But, while a reevaluation of Hardison may be overdue, Groff also will be heard by a Supreme Court whose current majority is so sympathetic to the interests of the religious right that it often advances those interests to the exclusion of all others.

Just one month after Justice Amy Coney Barrett’s confirmation gave Republican appointees a supermajority on the Court, for example, the Supreme Court handed down Roman Catholic Diocese of Brooklyn v. Cuomo (2020), which gave individuals who object to a state law on religious grounds unprecedented power to defy that law. The Court did so, moreover, at the height of a deadly pandemic, and the Roman Catholic Diocese case halted attendance limits at places of worship that were intended to slow the spread of Covid-19.

The Court, in other words, deemed the interests of religious conservatives to be of such transcendent importance that they justified abandoning public health measures intended to save human lives.

The stakes in Groff may seem lower at first glance — the case involves a postal worker who didn’t want to work on Sundays because of their religion. But the case could similarly empower conservative religious workers who seek accommodations from their employer that could disrupt that employer’s business or demean the religious worker’s colleagues.

Imagine, for example, a manager who refuses to hire gay people because of his faith, and who demands an accommodation permitting them to discriminate. Or a worker who insists upon preaching their conservative religious views about sexuality or gender roles to their colleagues, even when many of those colleagues feel harassed by this behavior.

Hardison, for all of its flaws, permits employers to forbid this kind of behavior — and even to discipline employees who claim a religious justification for behaving disrespectfully toward their colleagues. But Groff could fundamentally upend this balance of power, giving religious conservative workers the power to demand that their workplace culture be reshaped in their image.

The danger from Groff, in other words, is that the Court will overreach, replacing Hardison’s too-weak protections for religious workers with something that will give far too much power to the religious right.

Even fairly simple requests for a religious accommodation can disrupt a workplace

The Groff case involves a former postal worker, Gerald Groff, who wanted to be exempted from working on Sundays because of his religious beliefs (although the post office typically does not deliver mail on Sundays, the postal service contracted with Amazon in 2013 to deliver Sunday packages). In this sense, Groff is factually similar to Hardison, which involved a Saturday Sabbatarian who wanted that day off for religious reasons.

In many workplaces, especially workplaces with many workers who can share weekend work among themselves, accommodating a single worker’s request to have their sabbath day off would be no big deal. But the Justice Department, which represents the Postal Service in this case, argues that Groff’s request was particularly challenging to accommodate because he worked in a post office with only a few workers.

At one point, the DOJ explains in its brief, only four workers (including Groff) were available in Groff’s post office to cover Sunday shifts, and that included the local postmaster. One of Groff’s co-workers initially agreed to cover his shifts, but she was injured and was unable to continue doing so. Because Groff refused to work Sundays, that left just the postmaster and one other worker to cover Sunday shifts.

The fact that these other workers had to pick up additional Sunday shifts, while Groff refused to work on this day of the week, “created a ‘tense atmosphere” among other postal workers and led to “resentment towards management,” according to the local postmaster. According to the DOJ’s brief, one carrier transferred to a different post office “because he felt that it was not fair” that Groff did not pick up his fair share of Sunday shifts. Another mail carrier “resigned in part because of the situation.”

Thus, under Hardison’s “more than a de minimis cost” framework, there’s little question that the Postal Service should prevail in this case. Groff’s request for Sundays off appears to have caused his post office significant hardship, pitting workers against managers because of a circumstance that those managers could not control, and even causing workers to leave their jobs.

But Groff’s lawyers ask the Supreme Court to replace Hardison’s framework with one that is far more favorable to workers seeking religious accommodations.

If Hardison falls, what emerges in its place?

Groff’s attorneys’ primary argument is that the Court should import the legal framework that federal law already uses in disability cases and use that framework to govern workplace requests for religious accommodations.

Like Title VII of the Civil Rights Act of 1964, the federal law governing religious accommodations, the Americans with Disabilities Act also requires employers to accommodate workers with disabilities unless such an accommodation “would impose an undue hardship on the operation of the business.”

Unlike Title VII, however, the ADA actually defines the term “undue hardship.” In disability cases, an employer may deny a requested accommodation only if that accommodation would impose “significant difficulty or expense” on the employer. That’s a much higher standard than the one announced in Hardison.

Indeed, the ADA sometimes requires employers to make fairly expensive changes to a workplace in order to accommodate an employee with a disability. A 2015 federal appeals court decision, for example, determined that a call center that relied on software that was inaccessible to blind employees may need to pay at least $129,000 to accommodate those employees — an amount that the law quite reasonably can expect employers to pay in order to accommodate disabilities, but that is also far more than Hardison envisioned with its “more than a de minimis cost” rule.

But there are two reasons — one textual and one practical — to doubt that Congress intended the ADA’s “significant difficulty or expense” standard to also apply to workers seeking religious accommodations.

The textual argument against Groff’s position is fairly straightforward. The ADA states explicitly that an employer may only claim that a requested accommodation would cause an “undue hardship” if it would cause “significant difficulty or expense.” Title VII does not have similar language, which strongly suggests that Congress intended a different rule to apply to religious accommodation cases.

The practical reason, meanwhile, is that requests to accommodate a disability are fundamentally different from requests for a religious accommodation. The purpose of a disability-based accommodation is to ensure that a worker can do their job even if their disability might sometimes prevent them from doing so. A worker with carpal tunnel syndrome, for example, might request an ergonomic keyboard. Or a worker who uses a wheelchair might request ramps that will allow them to easily traverse the office.

The scope of a disability-based accommodation, however, is bounded by the nature of a worker’s disability. Once the worker with a disability is able to successfully perform their job with the same ease as an able-bodied worker, they have been accommodated.

Requests for religious accommodations, by contrast, are bounded only by an individual worker’s personal beliefs. And requests for religious accommodations can potentially infringe upon the civil rights of other workers, such as if a manager refuses to work with a gay colleague. Or if an executive follows the “Billy Graham rule,” the religious belief that men should not meet alone with women, even in a professional setting.

All of this said, Groff’s proposal to import the ADA’s “significant difficulty or expense” rule into religious accommodations cases does have one important virtue: At least it is a familiar standard that courts that already hear ADA cases know how to apply.

The Justice Department’s brief, by contrast, proposes a much looser set of guidelines that courts should follow in religious accommodation cases, such as a suggestion that an accommodation should not be required if a company would need to “regularly” operate short-handed or pay “premium wages to substitute workers” in order to accommodate a religious employee. That proposed rule would likely ensure that Groff loses his case, but it would offer little guidance to many courts hearing religious accommodation cases unlike this one.

If the Supreme Court does abandon Hardison’s “more than a de minimis cost” framework, whether in a decision that explicitly overrules Hardison or in a decision that “clarifies” Hardison in ways that fundamentally alter it, there is going to be a ton of litigation trying to figure out what the new rules mean for religious workers and their employers.

This uncertainty, moreover, might cause employers to err on the side of granting accommodations even in cases where doing so might harm another worker, such as the hypothetical case of an anti-LGBTQ worker who insists upon evangelizing to their queer colleagues. And a too-vague framework might also give ideological judges — the name “Matthew Kacsmaryk” comes immediately to mind — far too much leeway to impose their own conservative religious ideology on employers.

A post-Hardison world, in other words, is likely to be messy. And, while some messiness is inevitable whenever the Supreme Court replaces one longstanding legal rule with another one, the fact that the federal courts are so dominated by religious conservatives means that the new regime could be actively hostile to workers whose identities have historically been disparaged by those conservatives.

Groff could escalate the fight over whether the Roberts Court should follow Supreme Court precedents that Republicans do not like

The Supreme Court’s GOP-appointed supermajority has not, and this is putting it mildly, shown much loyalty to stare decisis, the doctrine that courts should typically follow previous decisions. In its last term alone, the Court overruled at least two seminal constitutional decisions: the abortion rights decision in Roe v. Wade, and Lemon v. Kurtzman (1971) which, for many years, protected the wall separating church and state.

Both Roe and Lemon, however, were decisions interpreting the Constitution, and the Court has historically been less reluctant to overrule constitutional precedents than it is to overrule decisions interpreting a federal statute. The idea is that, because the Supreme Court is the final word on constitutional interpretation, it should have some flexibility to correct previous interpretations that may be erroneous because no one else can do so. But when the Court misreads an act of Congress, Congress can itself step in to fix that error.

Hardison has very few defenders, but that does not change the fact that it’s been on the books for nearly 50 years and Congress has never amended Title VII to overrule it. Congress left Hardison in place, moreover, despite the fact that the legislature has been controlled by many shifting political factions over the course of the last five decades. And Congress passed quite a few civil rights and religious liberty laws during this period, including the ADA.

Under the ordinary rules governing stare decisis, Hardison should not be overruled. If Hardison truly butchered its interpretation of Title VII in a way that Congress deemed untenable, it would have stepped in by now to overrule Hardison.

Groff, in other words, could do more than just rework the rules governing religious accommodations in the workplace. It could potentially also rework the rules governing when the Supreme Court is allowed to abandon its longstanding interpretation of a federal statute, and to impose a new rule preferred by the Court’s current members.

And, in a Court like the current one, which is so eager to move fast and break things, that means that a whole lot could change very fast.