Critical support puts the emphasis on being critical. I have more problems with the Government of Russia than I have support for them but at the moment the majority of their focus seems to be on doing things I support. In many of the cases where I am critical of Russia I have no doubt that my criticism are correct.
China on the other hand I support. If I am being critical of their way of doing things I accept that there may be reasoning that I had not considered. I've only been actively practicing dialectical and historical materialism for a few years where they have a proven track record going back decades. Its more likely that I am wrong than the CPC.