How the gang's power enlarged.

I would pinpoint it at the end of 1974, coinciding with the fact that Premier Chou En-Lai became ill in 1974, and that Chairman Mao himself also at that time showed signs of illness and decline. So did practically at the same time Kang Sheng and Chu Teh. As for Marshal Lui Po-cheng, he is very old. Now the point is that all these people were members of the Politburo. So that when people ask how did the 'gang of four' get so much power, well, it is very easy to understand once you look at the composition of the Politburo. You'll realise that six of them were practically never there because they were in the provinces, that five or six of them were in bad health or declining and unable to attend. Therefore there was this bloc of these four who could practically run things because there was just nobody there to oppose them.