In my humble opinion, the key to the COM has nothing to do with city achievements or how much money you spend or what your political beliefs are. It doesn't matter what level you are on or how many universities you have. It is based on one simpler rule. though it isn't always easy to follow. I have read other players opinions and theories and in no way do I think mine is unique. Other people have also figured it out, its just that I was able to actually do it and the results spoke for themselves. So in order to score the most points and have the highest point assignments available, you must:
AT ALL TIMES YOU MUST CHOOSE THE ASSIGNMENT WHICH OFFERS THE HIGHEST POINT TOTAL CURRENTLY AVAILABLE. If you choose for example the 2nd highest task, once completed you will then receive an assignment of lesser points. Even if you go back to the highest point assignment that you didn't take previously, you will not be offered the assignments with the most points. No matter what, you must take the assignment offering the most points at that moment, it is the order that you take them in that matters most. When you complete an assignment with the highest points at the time, the next assignment you receive will be for more points than if you took the 2nd or 3rd highest one and then went back and chose the highest.
It is not always possible to always take the one with the most points, for many reasons. I was able to complete a contest taking all the highest point assignments and finished with my highest score ever by far. I think I had at least 10 different tasks worth 3000 minimum!