Why Have US Marxist-Leninists Abandoned Base Building?

Recently, there has been discussion about the absence of base building or “mass work” – deep organizing within the working class to prepare for socialist revolution – among Marxist-Leninist Parties in the US. But the construction of a mass base is a precondition for any socialist revolution, and in previous movements it was taken as a given that this mass work would make up the bulk of any communist party’s effort.