President Obama won re-election with the rock-solid support of what has become known as the "Obama Coalition" his hard-core supporters made up of: young people, minorities, women, and low-income voters.
The report at the link below says that without a high turnout of these groups Obama would not be in the White House today.
Now, little more than a year after the president's re-election, his job approval rating has fallen among all segments of the American electorate. But it has fallen the most among those who did the most to elect him.
Full report here.