What conditions in pre-CCP China can help explain the rise of Mao?

This could be a very long answer, but can be briefly summarised into several factors. Firstly, political conditions in China were dire, due to over 50 years of political turmoil and the disintegration of the ruling GMD, leading them to lose their support base, allowing many more people to flock to Mao. Secondly, military conditions also played a role, with the GMD's failure in fighting the Japanese creating national anger, and their poor military leadership provoking many of their force to desert and join Mao's Red Army. Finally, socioeconomic conditions in China were responsible for mass poverty, again turning more Chinese, especially peasants, towards Mao, easing his rise to power.