I'm referring to the lack of class-based voting in the US mostly. You can't quite tell a persons' partisan leanings in the US just by background or income.
Of course it's mostly referring to his claim the Democrats are the party of "rich gentry, trial lawyers and blacks" and the Republicans of everyone else, which is quite far from the truth. The only one of those which my 89% for Obama neighborhood has a significant number of is blacks and even then it's only about 25%, so there are clearly other people voting for the Democrats.
You left out the horde of government employees from your Dem checklist.