Comparing exit polls from 2004 and 2008 makes the breadth of Barack Obama's victory clear. Obama received a larger share of the vote than John Kerry among voters of all genders, races, education levels, and income classes, and virtually all religions. The only groups with whom he underperformed Kerry were older (65+) voters, and gay and lesbian voters.
Conversley, there is a hidden source of strength in this table that hasn't been talked much about before: Obama markedly overperformed Kerry among parents. In a sense, it was those people who have most reason to be concerned about the future who voted for Obama: people who are young themeslves, or people who have young children at home.