The Supreme Court heard arguments Tuesday for two cases that will determine if businesses are equivalent to people, and are thus exempt from providing certain services to employees in their health care plans.

The cases, known as Sebelius v. Hobby Lobby Stores, Inc. and Conestoga Wood Specialties Corp. v. Sebelius, grew out of sections of the Affordable Care Act, which require new health plans to pay for contraception and fertility treatments. Both Hobby Lobby and Conestoga are companies run by religious conservatives who object to the federal requirements. Hobby Lobby is owned and operated by David Green, who ranks on the Forbe's list of wealthiest people in the world, with a net worth of $5 billion.

At stake for businesses is whether they can, like people, claim a religious exemption from federal birth control requirements. A ruling in favor of Hobby Lobby and Conestoga would have broad implications for businesses, which could then presumably use their newfound personhood to discriminate against customers or employees whose lifestyles might be viewed as objectionable.

Among the central questions the arguments sought to address: To what degree does the Religious Freedom Restoration Act (RFRA) of 1993 apply to for-profit corporations? The act allows for individual exemptions from federal laws based on religion where the government is unable to prove a compelling interest, or where laws impose a substantial burden on an individual.

The arguments were presented by former Solicitor General Paul Clement, who argued for Hobby Lobby and Conestoga, and by the current Solicitor General Donald Verrilli, who represented the U.S. Government. Both attorneys have previously squared off before the Supreme Court, most recently in the ACA and marriage equality cases.

The solicitors presented arguments in a back-to-back marathon session lasting 90 minutes, where the nine justices indicated through questioning that they might split four against four, according to their liberal and conservative ideologies, with Justice Anthony Kennedy serving, as he frequently does in the most contentious cases, as the deciding vote.

Justice Sonia Sotomayor, for example, sharply questioned Clement about where he would draw the line for religious exemptions in the workplace.

"Is your claim limited to sensitive materials like contraceptives or does it include items like blood transfusion, vaccines? For some religions, products made of pork?" Sotomayor asked. "Is any claim under your theory that has a religious basis, could an employer preclude the use of those items as well?"

By contrast, Chief Justice John Roberts and Justice Antonin Scalia sought to undermine Verrilli's legal reasoning about whether corporations had the same rights to exemptions based on religion.

"The whole point of RFRA is that Congress wanted to provide exceptions for the religious views [in] particular--including proprietors, individuals," Roberts said.

For his part, Justice Kennedy suggested to Clement that a way around the issue could be for businesses to abstain from offering health care, and instead increase employee salaries by an amount that would allow them to purchase their own plans.

Liberal observers say a ruling in favor of Hobby Lobby could open the door to discrimination against employees and customers, for example unwed mothers or gay couples, to whom business owners might object on religious grounds. Conservatives say a ruling against Hobby Lobby could imperil the religious freedom of devout business owners.

The justices are expected to rule some time this summer.