Instead of talking about red and blue states. It is better to discuss red and blue counties. Democrats win in blue states like California and Illinois by winning with huge margins in just a few counties. The most interesting thing about those counties is that they are where the fewer middle class white live.  
 
Kerry received 90% of the vote in the District of Columbia. DC has virtually no true middle class or blue collar whites. Kerry received the votes of rich whites, government workers, and poor blacks.  
 
The pattern repeats itself in most states.

A better explaination occurs when you look at racial voting patterns.  
 
Democrats in 2004 received the majority of white votes in less than 10 states. Even in a blue state like California, a slim majority of whites voted for Bush.  
 
The Democrats are really three parties: Minorities who are disproportionately poor, the urban white elites to include wannabe elites such as most college students, college professors, and artisians; and the unions.  
 
In a state like Alabama that is now overwhelmingly Republican, the urban whites and the elite wannabes do not want to be associated with blacks,  
 
In a State like New Jersey, the elites, wannabes, and union workers do not associate as much with blacks and Hispanics. Thus, they are Democrats.

Look at the difference between ESPN and the Lifetime Channel or Oprah. Men learn from an early age the joking banter that men use to communicate. Women do not learn joking banter. There is no female version of Dick Vitale.