"Simple..."
You'll note that was a liberal site. There is no fury like that of the Left for a minority who leaves the leftist plantation.
I noticed that "two to three percent support among blacks" bit in there, too. This number, which hails from articles like this, is all over the Web now as a stone fact.
Note this paragraph in the very same article:
[Late Update: The Pew Research Center is just out with its latest poll, which has a larger sample, and it finds Bush's approval rating among blacks at 12 percent, down only slightly from 14 in July. Here are those results.]
In other words, "never mind."