Christian American employers appeared before the Supreme Court on Tuesday to challenge a law obliging firms to provide employees with health insurance that covers certain forms of contraception.
Judges are once again pondering the limits of the United States' constitutional division between church and state because of a disputed part of President Barack Obama's signature health reform.
The so-called "Obamacare" law obliges private employers to pay for employee health insurance that covers some kinds of contraception, a measure fiercely opposed by some Christian business owners.
And, predictably, the nine-member Supreme Court appears split between a liberal wing leaning towards a defense of women's rights and a conservative once sympathetic to religious belief.
The court's three liberal women justices took the lead in grilling the lawyers testifying during Tuesday's 90-minute-long hearing.
Outside the imposing Washington courthouse, dozens of protesters from both sides of the debate braved snow showers to gather on the court steps to chant their familiar slogans as the hearing began.
The religious freedom case was brought by craft store Hobby Lobby, whose billionaire chief executive David Green says his business cannot comply with Affordable Care Act rules.
Green, who describes his company as following "biblical principles," objects to requirements that it provide cover for specific emergency contraceptives and intrauterine devices to its 28,000 employees.
But the Obama administration, which exempted traditional religious congregations from the rule, says a for-profit company such as Hobby Lobby does not enjoy the same protections afforded to individuals under the US Constitution.
Arguing the case were the same lawyers who dueled last year over the heath act: Solicitor General Donald Verrilli representing the government and Paul Clement arguing for the plaintiff.
Four of the five conservative justices appeared sympathetic to Hobby Lobby, and only Anthony Kennedy's vote appeared uncertain.
He expressed concerns over both women's rights and the rights of family businesses opposed to abortion.
Warning of a "slippery slope," liberal justice Elena Kagan told Clement "you would see religious objectors coming out of the woodwork" if coverage could be denied for religious reasons.
Procedures like vaccinations or blood transfusions would be similarly targeted, not just contraceptives, she predicted.
Helen Alvare, Professor of Law at George Mason University School of Law, was appalled by Kagan's argument.
"Today it's contraception and early abortifacients...tomorrow it's all abortion, and the day after that it's assisted suicide drugs for an aging population," she told AFP.
"Religious actors, not the government, get to determine religious beliefs," she argued.
But conservative justice Samuel Alito asked Verrilli "what is inconsistent" about a for-profit enterprise and religious freedom.
Meanwhile, Kennedy noted that "the employee may not agree with the employer's religious beliefs."
But he worried that, under the government's argument, a private business could be forced to cover the costs of an abortion, which would be opposed by many religious Americans.
But government lawyer Verrilli retorted that two million US women rely on the contested methods as birth control and don't view them as abortions.
- Protesters on both sides -
Outside the court, protesters' vied for attention, with the various contingents flashing various talking points.
Feminist activists chanted and waved signs that read: "Birth control, not my boss' business."
Anti-abortion proponents, some in Amish or clerical garb, protested under the "my faith, my family" slogan, while feminists chanted and waved signs that read: "No bosses in my bedroom."
Hobby Lobby's Christian education business Mardel is also part of the suit, alongside another from Conestoga Wood Specialties, a Pennsylvania cabinetmaker whose owners say they run the company based on Mennonite Christian values.
The three firms risk a fine if they do not comply with the regulations.
The plaintiffs consider four of the 20 contraceptives covered under the Affordable Care Act -- two types of morning-after pills and two types of IUDs -- to be forms abortion.
The government's case was also backed by some liberal lawmakers, while conservative lawmakers support the plaintiffs.
A decision is expected in the end of June.