Why did large-scale urban centers fail to develop in pre-European North America?

Holocene North America (north of the Chihuahuan Desert) possessed all the makings of a continent capable of supporting a relatively dense population: temperate climates, ample precipitation, indigenous fowl and flora, and a smooth, irrigable terrain immensely amenable to horticulture. And yet, despite all the qualities of this gentle continent, its inhabitants fell short of developing their own versions of Teotihuacan, Monte Alban, Calakmul, Cusco, or Tiwanaku. Why did urban centers larger than Cahokia fail to develop in North America? Was the lack of wild teosinte such an insurmountable obstacle to urbanization that dragged them far behind their Mesoamerican and Andean cousins?