A national poll released Friday showed that voters who had heard or read about Senator Barack Obama’s speech this week on race relations and on his relationship with the Rev. Jeremiah A. Wright Jr. broadly approved of it.

Seven in 10 said Mr. Obama, Democrat of Illinois, did a good job talking about race relations, and as many said he did a good job explaining his relationship with Mr. Wright, according to the CBS News poll.

More than 6 in 10 said they mostly agreed with what he said about race relations in the United States, including a broad majority of Democrats and independents.

Fewer Republicans  4 in 10  agreed with the message.

Still, the poll showed some erosion for Mr. Obama. Just over half of registered voters now say he would be a president who is able to unite the country, down from two-thirds a month ago.