“ The leading Democratic measures of those years all received his hearty support. McDuffie, like Calhoun, became an eloquent champion of state sovereignty; but while Calhoun emphasized state action as the only means of redressing a grievance, McDuffie paid more attention to the grievance itself. Influenced in large measure by Thomas Cooper, he made it his special work to convince the people of the South that the downfall of protection was essential to their material progress. ”