You don't see it because poor white neighborhoods are rural. That's where most of the killings of poor whites happen.

King said this about the solution:

“In the treatment of poverty nationally, one fact stands out: there are twice as many white poor as Negro poor in the United States. Therefore I will not dwell on the experiences of poverty that derive from racial discrimination, but will discuss the poverty that affects white and Negro alike. ... I am now convinced that the simplest approach will prove to be the most effective — the solution to poverty is to abolish it directly by a now widely discussed measure: the guaranteed income.” — Martin Luther King