(CNSNews.com) - Denouncing what one activist called "white privilege," hundreds of protesters Monday demonstrated outside the U.S. Supreme Court in support of school racial quotas, while opponents of affirmative action said it was time to stop "tinkering with race."

The activists urged the justices to uphold race-based school admission practices in two cases under consideration by the court this term.

Most of the protesters were college students from historically black colleges and universities, including Howard University in Washington, D.C. The rally was sponsored by the National Association for the Advancement of Colored People (NAACP), the Rainbow/PUSH Coalition and several unions.

In both cases -- Parents in Community Schools v. Seattle School District No. 1 and Meredith v. Jefferson County [Kentucky] Public Schools -- white families sued the school districts because diversity programs kept their children out of schools in their neighborhood.

Under the programs, schools use race as a determining factor when approving school choice requests, favoring racial diversity in the schools over other factors, including the students' proximity to the school.

The Seattle policy allows school officials to use race as a factor when determining which students are admitted to the classrooms under school choice. It allows the officials to give preference to minority students in an effort to create racial diversity in the classroom.

The Kentucky school district's plan is similar but uses a quota system, requiring school officials to maintain a student body that is no less than 15 percent and no more than 50 percent African American.

In 1978, the Supreme Court struck down racial quotas in Regents of the University of California v. Bakke intended to make up for past discrimination, requiring that race-based admissions practices prove that they furthered students' education.

In Johnson v. Transportation Agency of Santa Clara County, California (1987), the court upheld minority "set-asides" in programs that sought to achieve gender balance in the county's workforce by favoring female candidates over male candidates.

In 2003, the court reaffirmed its opposition to quotas and in Gratz v. Bollinger ruled that race-based admissions systems must be "narrowly tailored."

The 9th U.S. Circuit Court of Appeals upheld the Seattle plan, ruling that "the district has a compelling interest in securing the educational and social benefits of racial (and ethnic) diversity."

Monday's protesters, organized by a group calling itself By Any Means Necessary (BAMN), said rejecting the policies would amount to overturning Brown v. Board of Education, the landmark 1954 decision that mandated racial integration of public schools.

Kim Gandy, president of the National Organization for Women, told the protesters they were part of a 40-year civil rights struggle.

"It was a long, hard fight to end segregation in this country," Gandy said. "We cannot return to segregated schools, yet that is where we are headed. We have to take action now. We cannot lose 40 years of struggle for equality and diversity and opportunity."

Gracie Lewis, an organizer from the Kentucky Alliance Against Racist and Political Repression, criticized Crystal Meredith, the white mother who sued Jefferson County Schools.

"It's all about white privilege. It has nothing at all to do about the Jefferson County School Board desegregation plan," Lewis said. "We are here to uphold the principles of Brown v. Board of Education in memory of Thurgood Marshall."

Marshall, the lawyer who successfully argued the Brown v. Board of Education case, later became the first African American to serve on the Supreme Court.

The rally was scheduled to feature speeches from Jesse Jackson and Al Sharpton. According to organizer Shanta Driver, however, Jackson was en route to Venezuela, where President Hugo Chavez won re-eelction Sunday. Driver offered no explanation for Sharpton’s absence.

Rainbow/PUSH Coalition spokesman Jerry Thomas said, however, that Jackson had not gone to Venezuela and had no plans to do so in the near future. The coalition had been actively involved in the protest, Thomas said, although he was unable to say why Jackson – who he said was in transit in the East Coast area – had not taken part.

While the protests went on with the support of BAMN, the NAACP and NOW, a few affirmative action opponents urged the court to overturn the policies.

"Regardless how well motivated, allowing the state to engineer racial mixing only creates racial stereotypes and increases racial tension," Terry Pell, president of the Center for Individual Rights, said in a statement.