Want a simple method for understanding top-level decision-making in China? Assume that the decision was made with the end goal of keeping the Chinese Communist Party (CCP) in power. While imperfect, it's the easiest way to explain why the CCP does what it does. It also offers a simple grading system for China news: the more a story touches on issues that threaten the survival of the party -- corruption, rural discontent, democracy movements, fissures in the CCP -- the more crucial they are to Beijing.
That's why the seemingly mundane updating of Hong Kong election rules -- which curb democracy in Hong Kong -- is a hugely important story.