How legions of fans have supported Bernie Sanders fundraising efforts and the lessons therein

SOMERVILLE, Mass. — While Bernie Sanders expresses disdain for big banks and other corporate lenders, some of the most valuable field lieutenants in the Vermonter’s political “revolution” are a band of techies here who have proven masterful at persuading Americans to make credit card payments. In a barely marked storefront location down the street from Tufts…