Indeed, in the earliest days of U.S. immigration, Irish, Italians, Jews and blacks alternately turned their hate on the group that fell at the bottom of the economic ladder. Today, new immigrant groups form pecking orders and biases.
"There are bad feelings between African Americans and blacks from the Caribbean and, historically, German Jews and Eastern European Jews hated each other," Levin said. "Much of it is economic. You find it in every group."
But, he said, the post-9/11 world and new global migrations have made Americans suspicious of all those who look or worship differently.
"It shocks people when you discuss this kind of hatred between groups that have suffered so much," Levin said. "But we should recognize that these groups consist of human beings who have weakness, frailties and prejudices. It shouldn't surprise us."
Americans are not the only culture to experience racial strife, according to Levin. When once-homogenous communities are threatened, they react protectively. Hate crimes are also on the rise in once-tolerant countries like Holland, Norway and Sweden.
The Atlanta murder case — an Indian father accused of killing his black daughter-in-law — is an extreme example of the phenomenon, according to Levin. "Not only did an outsider move into a neighborhood, she moved into the family," he said.
Eight year's after her mother's murder, Sparkle's daughter is "doing great," according to her adopted mother. "She's innocent to all this," said Lowry, an Atlanta television reporter. "She knows me as 'mom' since she was 6 months old. Her mother is 'Sparkle,' and knows she was killed by a bad man."
Meanwhile, Amardeep Singh and the Sikh Coalition are working to address the harassment of their own community in a post-9/11 world. Their recent survey of 1,000 New York Sikh children revealed "significant" harassment at school.
"Folks recognize that it's not OK to use the 'N-word' or there will be negative repercussions, and if you are anti-Jewish, you get in trouble," Singh said. "But calling a kid a terrorist or Bin Laden is not just a racial epithet. It's justification for degrading a person."
Still, he doesn't defend Chiman Rai for his alleged crimes.
"It's sad that a minority like the South Asian community has taken on the prejudices of the majority community," Singh said. "You'd think members could rise above that. But we recognize the commonality of the experience in the U.S. to fight bigotry."
"There is no community that is immune to prejudices," he said. "It's a sad part of the human condition."
ABC News researcher Suzanne Bernard contributed to this report.