Young and emerging artists often dream big. They share ideas and hope to one day establish a groundbreaking group or movement in the grand tradition of their forebears, be it Cubism and the European avant-garde at the 1913 Armory Show, the Dada manifestos that established a whole new way of thinking about art, the Abstract Expressionists at Cedar Tavern, or the proliferation of Pop and, later, street art. Few of these dreams amount to much as the dreamers fumble for a cohesive, culturally significant hook on which to hang their proverbial hat — let alone an educated, well-connected champion to push their ideas onto the world stage, as Clement Greenberg…