Americans are sharply divided by race heading into the first election in which an African-American will be a major-party presidential nominee, with blacks and whites holding vastly different views of Senator Barack Obama, the state of race relations and how black Americans are treated by society, according to the latest New York Times/CBS News poll. The results of the poll, conducted against the backdrop of a campaign in which race has been a constant if not always overt issue, suggested that Mr. Obama’s candidacy, while generating high levels of enthusiasm among black voters, is not seen by them as evidence...