Why Isn't Obama Further Ahead?

Barack Obama has less of a lead over John McCain than would be suggested by his advantages in party affiliation and by President Bush's disapproval numbers, writes Gary Langer of ABC News. Among other things, data from a new poll show Obama has not received a major boost from Hillary Clinton's endorsement, suggesting he still needs to work to recruit her supporters.

Only about half of Americans say that they think Obama is experienced enough to be president, and Obama and McCain are running about even among independents. Still, likely voters favor Obama to deal with a majority of issues raised by the poll, and Obama has vastly more supporters who call themselves "enthusiastic" about his candidacy.