Republicans were more likely than Democrats and independents to disagree.

Seventy-four percent of Democrats say the move was the right decision, compared to 19 percent who say it was not. Independents were more closely divided, with 53 percent backing the removal and 37 percent opposing it. Republicans are slightly more opposed to the removal (49 percent) than supportive of it (43 percent).

When asked to explain their feelings on South Carolina’s decision, 36 percent of respondents who view removing the flag as the right decision cited its association with racism, hatred or slavery, while 20 percent said the flag was offensive or divisive. Of those who say the decision to remove the flag was wrong, 54 percent mentioned its historical significance, while 27 percent said it is a misunderstood symbol.

The survey’s release precedes the anniversary on Sunday of the death of Michael Brown, an unarmed black teenager who was shot and killed by a police officer in Ferguson, Mo. His killing on Aug. 9 last year was one of a string of deaths of African-Americans at the hands of the police or while in police custody that have fueled a national debate over the role of race in policing.

The killings might have contributed to a shift in views on the country’s racial progress from President Obama’s inauguration as the first African-American president. Half of Americans describe racism as a big problem, according to the poll, more than twice as many who said the same in January 2009, when Mr. Obama took office.

“This shift in public opinion is seen across the board,” the study’s authors said. “Growing shares in all regions of the country, and across all demographic and partisan groups say both that racism is a big problem and that more needs to be done to achieve racial equality.”