Tomorrow the Supreme Court hears arguments in one of the most anticipated cases of the term, Hobby Lobby v. Sebelius. The focus of the case will be on President Obama's health care law and its requirement that employers provide health insurance that includes coverage for birth control. Yet, what the case is really about is the future of gay rights.

Hobby Lobby is a crafts store chain whose owners have religious objections to certain forms of birth control. Under regulations adopted by the Obama administration, the company is required to offer comprehensive health care including several forms of birth control that Hobby Lobby's owners believe cause abortion. The company has challenged that requirement under a federal law designed to protect religious liberty, the Religious Freedom Restoration Act, or RFRA.

The advocates in the courtroom tomorrow will focus on a number of important questions: Are corporations "people" with religious beliefs? Should business owners be able to assert religious beliefs if it means that employees will be adversely affected? Does the law's exemptions for churches and other religious institutions mean that Hobby Lobby too must be granted one?

The most important question raised by the case, however, may be one the lawyers overlook: Can business owners use religion as an excuse to discriminate against LGBT people? If the Supreme Court rules in favor of Hobby Lobby, the answer may well be "yes."

We're already seeing a spate of proposals at the state level for Jim Crow-like laws that would permit discrimination against LGBT people. A few weeks ago, Arizona legislators made headlines when they passed a law that would enable such discrimination. That law was vetoed by Arizona's governor but similar proposals have cropped up elsewhere, including Kansas, Mississippi, and Georgia.

These laws represent a dangerous and radical break from our national commitment to equality. We don't allow businesses to discriminate on the basis of race, sex, or a number of other protected categories — even if the business owners have religious objections. A company run by Quakers can't refuse to do business with veterans. One run by Muslims can't refuse to do business with Jews. Business owners who believe women belong in the home can't refuse to hire women.

Yet allowing Hobby Lobby to disregard the Affordable Care Act on the basis of its owners' religious beliefs could make Arizona's anti-LGBT bill the law of the land.

Business owners around the country would be able to point to Hobby Lobby's victory and claim that they too have the right to disregard the law in order to vindicate their personal religious beliefs when it comes to LGBT people. Having to serve or sell goods to someone is at a least as "burdensome" as including birth control — which, in this case, comes at no additional cost to the employers.

After gay marriage, the highest priority for the gay rights movement is ending discrimination in the workplace. Supporters in Congress have proposed the Employment Non-Discrimination Act, or ENDA, which would add sexual orientation to the list of protected categories under federal law. The Obama Administration has also considered new regulations to prohibit federal contractors from discriminating against gays and lesbians.

The Hobby Lobby case suggests exactly how such anti-discrimination laws would be undermined if any employer could claim a religion-based objection to the law. This is especially so if the Supreme Court accepts the reasoning of the lower court, which also ruled in Hobby Lobby's favor.

That court held that the government had to exempt Hobby Lobby from the birth control requirement because the law had numerous other exceptions, such as those for churches and other explicitly religious institutions. Given that other entities were exempt, the government couldn't be said to have a compelling reason to justify the burden on Hobby Lobby's owners.

The same logic would apply to ENDA and similar laws. Federal anti-discrimination rules also have numerous exceptions. For example, the federal ban on race and sex discrimination in hiring only applies to employers with 15 or more employees, exempting the majority of small businesses. Religious institutions and private clubs are also exempt.

Such exceptions are a normal part of the give-and-take of legislation. They should not be read to mean the government lacks a genuine interest in combatting discrimination — or providing comprehensive health insurance.

Sixty years ago this May, the Supreme Court struck a decisive blow against Jim Crow when it struck down school segregation in Brown v. Board of Education. Will the Supreme Court mark Brown's anniversary by ruling in Hobby Lobby's favor and ushering in a new era of legally sanctioned discrimination?