Sometimes being a Supreme Court justice looks like the most glamorous job in the world. Robes! World travel! Life tenure! Adoring clerks! But other times, it all comes down to parsing the semicolons. And today was one of the semicolon days, as the court probed whether an employer is required to treat pregnant workers better than, worse than, or similar to the nonpregnant workers to whom the employer offers accommodations. Oral argument turned into an hourlong, hypertechnical inquiry into statutory construction and, eventually, the precarious balancing of two clauses against a semicolon.

UPS hired Peggy Young as an “air driver” who delivered chiefly small packages in 1999. When she became pregnant in September of 2006, her doctor advised her not to lift parcels greater than 20 pounds for the first 20 weeks of her pregnancy; after that, she should not lift more than 10 pounds. UPS refused to allow her to keep working her normal job since she couldn’t lift heavy packages, and the company refused to reassign her to light duties. She was put on unpaid leave and lost her health benefits and pension. She returned to work after the birth of her baby and sued UPS in 2008 under the federal Pregnancy Discrimination Act.

As Gillian Thomas explained earlier this week, the PDA, passed by Congress in 1978, amended Title VII of the Civil Rights Act. The act was in response to a 1976 Supreme Court ruling that found pregnant women were not protected under laws that prohibit sex discrimination because their pregnancy had nothing to do with gender. The PDA requires that employers treat “women affected by pregnancy” the same as “other persons not so affected but similar in their ability or inability to work.”

Young lost on summary judgment (meaning there was no trial) at the district court and again at the 4th U.S. Circuit Court of Appeals in Richmond, Virginia, which held that the PDA does not give pregnant women “a ‘most favored nation’ status.” Nobody disputes that some UPS workers were granted accommodations when they were hurt. UPS policy was to accommodate employees with light-duty assignments if they were either injured on the job, qualified as disabled under the Americans With Disabilities Act, or lost their federal driver’s certificate. (The company has since voluntarily changed its policy to accommodate pregnant employees.) Young fit into none of these categories. The question is whether the PDA requires that Young be compared with those workers or only that UPS not discriminate against pregnant women based on an animus toward them.

It quickly became clear today that in the absence of a fully developed trial record and facts, it’s going to be very difficult for the justices to wrestle the statute to the ground. The lawyers dispute who even got accommodations at UPS and also why they got them and also who didn’t get them and why. As Justice Stephen Breyer notes toward the end of the session: “Why don’t we have to look at the facts?” He notes that “if it turns out that they’re right, that there were four people who weren’t pregnant, and that’s all, who didn’t get the benefits, that’s pretty strong evidence that the employer is discriminating. If there were 400,000 people who got the thing off the job and there were only, like, 19 people on the job who got the benefit, well, then you have a better case.”

Young is represented this morning by professor Sam Bagenstos of the University of Michigan, who opens by noting that “if Peggy Young had sought an accommodation for a 20-pound lifting restriction that resulted from any number of conditions, whether acquired on or off the job … UPS would have granted that accommodation. But because Peggy Young’s 20-pound lifting restriction resulted from her pregnancy and not from one of those conditions, UPS rejected her request.” Justice Anthony Kennedy immediately accuses him of “giving a misimpression” of the record, but Bagenstos replies that the record shows that UPS would have given the light-lifting accommodation to employees with on-the-job injuries as well as to drivers who’d incurred off-the-job injuries.

Justice Antonin Scalia asks whether, as the 4th Circuit held, this gives pregnant women “most-favored nation status.” He wonders whether, if the company has a policy under which “your senior employees are driven to work when they are unable to drive themselves,” you have to do the same for pregnant women? Breyer similarly wonders whether pregnant women are entitled to the same benefits given to a truck driver who has “driven over a particularly difficult mountain pass … and gotten himself in some danger.”

Bagenstos explains that it’s discriminatory to treat pregnancy-related conditions less favorably than other medical conditions and that UPS, by providing accommodations to “three very large classes of employees … who are not pregnant, is treating pregnancy-related conditions less favorably than other medical conditions.”

Breyer, explaining that he is selfishly trying to get others to help him figure out what the opinion should say, explains that a rule providing that “if you give a lot of benefits to a lot of employees, but not to the pregnant women, and you don’t give it to some employees and not to the pregnant women, and the employer says, ‘Look, pregnant women are like the few we don’t give it to, not to the lot we do give it to,’ employer, you lose,” doesn’t make much sense. He also says that “by the time I’ve written that into the U.S. Code, nobody knows what I’m talking about.”

Nobody knows what he is talking about.

Solicitor General Donald Verrilli has 10 minutes to argue on Young’s behalf. He takes some heat because his office has switched positions on this issue in recent months. (“Because we’re evolving” is not an answer, by the way.) Verrilli explains that the whole point of the PDA “is to reduce the number of women who are driven from the workforce or forced to go months without an income as a result of becoming pregnant.” It’s critical to understand that even though the Equal Employment Opportunity Commission, nine states, and UPS have now changed their policies to afford greater protections to pregnant women, as more and more women work, especially in demanding, physical jobs, these accommodations matter more and more. According to the Census Bureau, an estimated 62 percent of women who had given birth in the previous year were in the labor force, and women are the sole or primary breadwinners in 40 percent of American families with children, according to a Pew study. Verrilli adds that “the one thing an employer can’t do … is draw distinctions that treat pregnancy-related medical conditions worse than other conditions with comparable effects on ability to work.”

Finally, Caitlin Halligan has 30 minutes to represent UPS. Her argument is that failure to accommodate doesn’t make UPS discriminatory but rather “pregnancy-blind.” Halligan will spend much of that time being pounded by Justice Elena Kagan, who—in a protracted one-on-one—will ask her 10 different versions of this same question: “So your reading of the statute basically makes everything after the semicolon completely superfluous?” (The troublesome semicoloned sentence is, admittedly, a little clunky: “The terms ‘because of sex’ or ‘on the basis of sex’ include, but are not limited to, because of or on the basis of pregnancy, childbirth, or related medical conditions; and women affected by pregnancy, childbirth, or related medical conditions shall be treated the same for all employment-related purposes, including receipt of benefits under fringe benefit programs, as other persons not so affected but similar in their ability or inability to work, and nothing in section 2000e-2(h) of this title shall be interpreted to permit otherwise.”) Kagan slowly builds to the accusation that under Halligan’s reading of the statute, everything after the semicolon is a “kind of double redundancy.” It’s a redundancy, if you will, that “that becomes redundant even within the redundancy.”

Ah. The glamour.

Justices Ruth Bader Ginsburg and Samuel Alito take turns asking Halligan what the words after the semicolon mean, with Ginsburg finally challenging Halligan by saying: “You said that—that Young’s position is ‘most favored nation.’ Well, yours is least favored nation, right?”

Kagan, who has been a one-justice Tasmanian devil all morning, concludes by informing Halligan: “What we know about the PDA is that it was supposed to be about removing stereotypes of pregnant women as marginal workers. It was supposed to be about ensuring that they wouldn’t be unfairly excluded from the workplace. And what you are saying is that there’s a policy that accommodates some workers, but puts all pregnant women on one side of the line.” This is why pro-life and pro-choice groups and most women’s groups have crossed the ideological divide to support Young in this case: The PDA was intended to prevent women workers from being forced to choose between their jobs and their babies.

Even Alito seems to start to worry that the facts here have not been developed at trial, asking Bagenstos in rebuttal: “You really think that you could prove at trial that if somebody is injured in a recreational activity over the weekend, that they get light duty but a pregnant women does not, maybe?” Bagenstos says yes. Bagenstos concludes as follows: “You have to treat pregnant workers as just as valued employees as anybody else, and if you think it’s valuable to keep these employees on the job who are injured on the job because they keep valuable knowledge within the company, do that for pregnant women.”

Nobody is quite sure, following argument, how the votes add up or what possible test the court might set out to resolve the issue, even if it sends the case back to the lower court for a full trial. What is clear is that the justices are treading softly, in ways that haven’t always been in evidence in gender and employment cases. That’s a good start.