Two days after the nation commemorated the legacy of Dr. Martin Luther King, Jr., the Supreme Court heard oral arguments in a case that could cripple a key Civil Rights law that was passed in King's honor.

On Wednesday, the Supreme Court justices heard a one-hour oral argument on the landmark 1968 Fair Housing Act, which was passed to combat housing discrimination in the immediate aftermath of King's death. Under the law, it is illegal to "make unavailable or deny, a dwelling to any person because of race," reports CNN. While there is no question that the law was meant to ban open discrimination in the sale and rental of housing, the Court will decide if the law also covers racial and other bias claims that produce an unintentional discriminatory effect, which are known as "disparate impact" claims.

Civil rights groups are concerned that should the Supreme Court not interpret the law to include the broader definition, then it will make it more difficult for people to file housing discrimination claims under federal law.

"The FHA was passed for the purpose of dealing with both intentional discrimination, but also to deal with the effects of discriminatory policies that end up perpetuating segregation," said John Relman of the National Fair Housing Alliance at a recent press conference.

The case began in 2008 after the Inclusive Communities Project, a nonprofit aimed at promoting racial integration in Dallas, accused a Texas agency of allocating tax credits to developers who build low-income housing projects. In a lawsuit, ICP said that the agency violated the FHA by disproportionately awarding the tax credits to properties in working class areas dominated by people of color, reports Reuters.

Lower courts ruled in favor of the ICP, but Texas filed an appeal to the Supreme Court, arguing that the FHA predates disparate impact claims.

"There is no language anywhere in the Fair Housing Act's anti-discrimination rules that refers to 'effect' or actions that 'adversely affect' others," wrote state lawyers in court briefs. They argue that the FHA only forbids actions that "discriminate because of race," and not actions that "discriminate because of any factor that happens to be correlated with race."

The Obama administration has also chimed in, noting that the Department of Housing and Urban Development also interprets the FHA to allow disparate impact claims.