Since you do not directly control the votes of governors in your provinces, it is not possible to give orders on the Council of Governors Screen.
You are guaranteed the support of all owned provinces if your great power is nominated. However, if two other great powers are the nominees, governors of your provinces decide to vote or abstain based on the performance of the rulers of the nominated great powers.
To ensure that your nation is nominated, you need to develop a lead in industrial strength. To obtain maximum support once you are nominated you need military success, diplomatic success, or a mixture of both.
