The Democrat Party feeds on economic, social, and racial discontent and resentment.  
It is why it exists. 
The Democrats are invested in a very unhealthy ideology: 
Feeling sorry for yourself and always blaming the "other guy' for your own failures. 
As long as people are poor and needy, the Democrat Party survives and thrives.  
The moment these same people acquire some social and economic status, they realize that the Democrats want to meddle in their affairs and hold them down.  
That's why so many grandchildren of immigrants are Republican and not Democrat.  
Once they "make it," they know that the Democrats are only useful on the way up, but not when they've "arrived."