Football already is a sport watched by (and commercially payed for by) the middle class that's largely played by the poor, since at least the mid-90's, and probably the 80's as well. Take a look at who plays competitive NCAA football, and who from there goes into the NFL draft -- or watch a bunch of "30 for 30" about football (because anecdata is generally more entertaining) and the trends are clear. There are a few key position outliers, by now whittled down to "quarterbacks, who have a host of special rules and how they can't be hit".