Wash/abc Poll Obama bounch by adding 15% additional black respondents

This Washington Post-ABC News poll was conducted by telephone September 19-22, 2008, among a random national sample of 1,082 adults, 916 registered voters and 780 likely voters. The survey includes additional interviews with randomly selected African Americans, for a total of 163 black respondents. The added interviews (commonly referred to as an "oversample") were completed to ensure there were enough African American respondents for separate analysis; the group was not over-represented in the reported results from the full sample. The results from the full survey have a margin of sampling error of plus or minus three percentage points. Error margins are higher for subgroups. Sampling, data collection and tabulation by TNS of Horsham, Pa