Think federal farm subsidies only help out struggling family farmers? Think again. Fifty members of the Forbes 400 list of the richest Americans—banking tycoon David Rockefeller Sr., Microsoft co-founder Paul Allen, stockbroker Charles Schwab and dozens of other billionaires—received at least $6.3 million in farm subsidies between 1995 and 2014, according to an Environmental Working Group (EWG) analysis. And these fat cats likely received even …