In a case that could reshape America's civil rights and employment practices, the U.S. Supreme Court has heard arguments on the propriety of race-based considerations when it comes to promoting workers. The case involves mostly-white firefighters who say they have been unjustly penalized by a city's application of civil rights laws designed to promote a diverse workforce.

It is a question debated in the United States for decades: to what lengths should employers go to ensure that racial and other minorities are hired and promoted? And do those efforts discriminate against the non-minority population?

The case in point involves 20 firefighters from New Haven, Connecticut. In 2003, the city administered a test to determine eligibility for command positions in the force. No black firefighters passed the test, which consisted of a multiple-choice exam and an oral question-and-answer section.

The city opted to throw out the rest results and suspend firefighter promotions, citing US civil rights law that prohibits employment practices that harm minorities. That decision prompted 20 firefighters who passed the test to sue. Nineteen of the plaintiffs are white and one is Hispanic. Lower courts dismissed the lawsuit, prompting the case's elevation to the Supreme Court.

Attorney Karen Torre represents the plaintiffs. She spoke with reporters after more than an hour of oral arguments before the high court.

"A number of things are at stake: the core right of every American to be treated as an individual, and not categorized and labeled because of his or her skin color," said Karen Torre. "And the right of the public to be protected by public safety commanders chosen strictly on the basis of merit, not on the basis of skin color. Firefighters have the most dangerous job in this country, and the least that we can do is to make sure that they are led by the most competent, knowledgeable and educated commanders."

But the city argues the racially-disparate test results indicate that the exam was flawed in either its construction or its execution. Lawyers for New Haven's municipal government say, had they gone ahead with the promotions based on the test results, they would have faced a lawsuit from black firefighters alleging discrimination.

Attorney Dennis Thompson represents the International Association of Black Firefighters, which wrote an amicus brief to the Supreme Court backing New Haven's decision. Thompson says employers, including municipal governments, have a duty to promote diversity.

"Diverse organizations are better organizations," said Dennis Thompson. "They make better decisions. They actually respond better and they are more cohesive. We think that diversity is essential to the performance of the fire service in this country. We think it is of compelling state interest, and we think it is an issue of national security, because these are our first responders [in an emergency]."

Observers who attended the oral arguments noted a lively exchange between the Supreme Court Justices and the attorneys. Legal scholars say the case will likely divide the court between its liberal and conservative justices, with moderate-conservative Anthony Kennedy possibly serving as the deciding vote in the 9-member body. The Supreme Court has several options, including sending the matter back to a lower court for trial.

This is the first case involving questions of race to reach the high court since Barack Obama became president.