It's human nature to support someone who gives you free stuff. It's also human nature to slack off when your basic needs are provided for. The Democrat Party has exploited these human traits and focused them on blacks; this strategy has been much more successful than their past initiatives (slavery, segregation, terrorism) at destroying black families.
The Democrat Party's strategy works with any special interest group, be it gays, illegals, blacks, unions, corporations, etc. Give a group special privileges and individuals in that group will overwhelmingly support you.