Old Sources of Democrats' Decline

Indeed, Reed's article, Kazin adds, "illustrated a key transition in the history of the American left." The journalist Reed and the politician [William Jennings] Bryan agreed on most economic issues, and yet the divide on matters "literary, philosophical, and sexual" was simply too deep. In other words, Reed's enthusiasm for lefty economic justice yielded to his far greater enthusiasm for avant-garde bohemian living. Thus the split between the Old Left (socially conservative, even puritanical) and the New Left (socially libertarian, even at the expense of class consciousness)--which would define the politics of the later 20th century--was visible even before the Russian Revolution.
-James Pinkerton, "New Deals and Old Answers"