As of 2003, one of the most advanced revolutionary struggles in the world is that led by the Communist Party of Nepal (Maoist). The CPN(M) launched a People's War against the current semi-feudal Nepalese regime on February 13th, 1996, and major progress has been made in mobilizing the Nepalese masses in revolution. Not only has the People's War been progressing very well overall, but there is clear evidence that the great masses of Nepalese people have been brought to support that war. This can be seen, for example, in the very successful bandhs (general strikes) against the reactionary state that the CPN(M) calls for from time to time.
It is not yet completely clear to me how the term mass line itself is being used by revolutionaries in Nepal, though it seems obvious that what I would call the mass line, namely the method of revolutionary leadership which is also known as the method of "from the masses, to the masses", is definitely being widely used by the CPN(M). An illustration of this comes from the following anecdote related to me by a friend:
There was a conference of anthropologists working on/in Nepal a year or two ago. A number of these anthropologists were working in villages that CPN(M) cadre came to. These anthropologists came to the conclusion that really, the Nepalese people are not fighting for Maoism. Why? Because the CPN(M) cadre who came into these villages were remarkably adept at identifying the issues of concern to these villagers and uniting the villagers in struggle around these issues, not around "struggling for communism."
Apparently these bourgeois anthropologists are completely ignorant of the Maoist mass line method which connects up the immediate and short-term interests of the masses with their long-term (revolutionary) interests. They don't understand that this is the way to lead a revolution that brings about socialism, and eventually communism.
But while the Nepalese Maoists are using this powerful leadership method, they appear to be using the term 'mass line' itself in a more general sense, to mean something like "involving the masses themselves in struggle".
In an interview in 2001 in a newspaper in India, Comrade Prachanda, the Chairman of the CPN(M), said that "Another distinguishing feature of a Maoist movement is the pursuance of the mass line, or the involvement of the large masses of people in every military and political action..." [See "Interview with Chairman Prachanda", The Worker, #7.]
A similar use of the term 'mass line' is reflected in the report Comrade Prachanda gave to the Second National Conference of the CPN(M) in 2001. (See below.) In this report Comrade Prachanda refers to how the Party is organizing and leading struggles of various sections of the masses, including women, national minorities, workers, students, the intelligentsia, artists and cultural workers, and so on.