Living in Philadelphia, I can say that Jones is absolutely on the mark as far as what happened here to make a 80% white Republican dominated city a 55% minority Democrat dominated city.
The Democrat City governments elected since the 1960's have purposefully attacked white ethnic neighborhoods with a variety of programs to drive out the inhabitants.
Most recently, under Rendell and Clinton starting in 1993-4, a full frontal attack was made on Overbrook Park, Oxford Circle, Juniata Park, Lower Mayfair, Northwood, and Crescentville, with the city encouraging Section 8 criminals and other assorted lowlifes to move in and purposefully working to undermine hiterto stable ethnic neighborhoods (mostly Republican neighborhoods too - surprise, surprise). Tactics like withdrawing Police Officers from precincts in these neighborhoods, encouraging no down payment/no closing cost realtors to attack the blocks, etc., etc.
Many people around here are very bitter about how this has all played out.
They were starting to dump section 8'ers in my Brooklyn nabe, but that had more to do with landlords who needed the income to offset the rent controlled apartments where you had 80 year old ladies paying $250 in rent for a place that they could get $1,000 from HUD for.