The roiling American border debate over immigration has revived one of the ugliest chapters in American history and become a vital recruiting tool for hate groups, experts say.
The number of hate groups -- from the Ku Klux Klan to neo-Nazis and skinhead groups -- has risen by 40 percent since 2000, from 602 to 844, according to the Southern Poverty Law Center, which tracks such groups.
And they've turned their jaundiced eye toward Latin Americans, particularly Mexicans, in an alarming number of apparent hate crimes.
Watch the full report on hate crimes on "World News With Charles Gibson" tonight on ABC.
Take David Ritcheson, 16, a Mexican-American football star born in Houston. He was beaten nearly to death by two skinheads at a teen party. They poured bleach on him and beat him mercilessly. Ritcheson was in a coma for days, and suffered massive internal injuries, internal bleeding and a shattered cheekbone. He is now deaf in one ear.
"I just didn't expect my race to become a situation," Ritcheson told ABC News senior Law & Justice correspondent Jim Avila.
Ritcheson testified before a congressional committee last month about the need for stronger hate crime legislation.
"I don't think there's any question at all that hate crimes against Hispanics and anyone really perceived to be an immigrant are very much on the rise," said Mark Potok of the Southern Poverty Law Center.
The fear is real -- an undercover video taken by the Bureau of Alcohol, Tobacco and Firearms and obtained exclusively by the ABC News, shows a klansman building a pipe bomb.
"All you've got to do is put the insides in and the powder," klansman Daniel Schertz can be heard telling an undercover agent. Schertz was later arrested for selling five pipe bombs that agents watched him make. He allegedly told an agent that he hoped the bombs would be used to blow up a bus full of Latinos. He was sentenced to 14 years in prison.
Ellen Davis, Mary Harris, Gina Sunseri and Lauren Pearle contributed to this report.