Of course organized labor, at its greatest exten, was NEVER more than a very small part of the total working class. And the "left" elements inorganized labor were never more than a small part of that labor force. So the legt's "historic base" was a trivial part of the population from the very beginning. I would ascribe this to the ideolgical, economic and cultural power of Capital, not to "mistakes" on the part of leftists of the past. They worked within limits externally imposed on them. But leftists of the present do _nnot_ have these limits imposed on them (as the great explosion of "The '60s" demonstrated. So if leeftists today allow this 'historic' practice to dominate their thought, then they are _by choice_ making themselves irrelevant to the class struggle.
Carrolk