U.S. President Barack Obama said on Friday he should have chosen his words more carefully when he said police "acted stupidly" in arresting a prominent black Harvard scholar.
Several U.S. presidents and candidates have been embroiled in disputes over race, a touchy subject in a country with a history of slavery and racial segregation. The disputes often center on charges that a politician's words are divisive.
Following is a list of some of the disputes over race:
-- Obama's campaign was rocked in March 2008 by the emergence of sermons by his former pastor Jeremiah Wright in which he said "God damn America" and castigated the country for its racial policies.
Many voters said Obama's long association with Wright put his judgment and trustworthiness in doubt. Obama gave a wide-ranging speech on race in a bid to dispel concerns.
-- Former Senator Hillary Clinton's presidential campaign was hit by several disputes over race. In May 2008 she noted her electoral appeal among "hard-working Americans, white Americans," language she denied was divisive. Clinton now serves as secretary of state.
-- Former President Bill Clinton compared Obama's win in South Carolina's primary in January 2008 to the victories of civil rights leader Jesse Jackson in the state in 1984 and 1988. Critics said Clinton was belittling black voters, a charge Clinton denied.
-- In February 2007, then-presidential candidate Joseph Biden described Obama as "articulate and bright and clean." Critics said his words were patronizing. Biden apologized. He is now vice president.
-- As a presidential candidate, Bill Clinton responded strongly in 1992 to comments by hip-hop artist Sister Souljah about white people. His comments were criticized by Jackson and were seen as subtle appeal to independent, white voters.
-- Supporters of former President George Bush ran TV adverts during his 1988 campaign about Willie Horton, a black convicted murderer who raped a woman after he was released on furlough in Massachusetts. The ads attacked Bush's opponent Michael Dukakis, the governor of Massachusetts, as soft on crime. Critics said the use of Horton played on supposed white fears about black criminality.
(Writing by Matthew Bigg; editing by Jim Loney)