Usually, in dreams and visions, a president of a country represents a person that you and others respect a lot. Such a person is regarded as a person of power, influence, and far-reaching abilities. It is usually a person who is the leader of a ministry (spiritually) and if it is the president of the USA, in the dream, (even an ex-president) it speaks of a person who is regarded the most influential in his area of expertise or ministry.
Asking him to give you his autograph is just a way of showing him that you have respect and appreciation and honor for him. It actually means you have respect for what he does and that you even want to do what he is doing.
The fact that you could see every pore in his face speaks of you watching his behavior, actions, and even his personality very closely. You are quite aware of how he is and what his characteristics are. If this is not the case, maybe you should. It is almost about what Paul said: We should imitate each other like he imitated Christ.
You wanted something from him (you show appreciation and respect by asking him for his autograph but his autograph represents something that belongs to him that he gives to you). He did not give it but then he suddenly realized that you should have it, because he saw your disappointment (“saw” means God gave him insight), and, he probably realized that God probably predestined that you should be equipped with the resources that he gave you. Signatures in dreams and visions speak of approval and authority. So his approval (signature) could have a significant impact on your life. He was also interested in you, that is why he asked you questions about your ministry and your calling, knowing that God might use the resources that he gave you (approval, assistance, being an example to you, and the other spiritual resources that he told you to wait for) in a wonderful way to equip you for ministry. The dream did not reveal what the other resources were, but it must be something that will equip you for ministry and help you with your calling.
You answering him in a funny confused way and almost not the complete truth symbolizes that you need assistance in this area. You do not really know yet what God wants for your life. This person will help you in this area. He will probably be able to guide you in this area so that you can be sure of your calling and the way that you must go.
This person is helping many people in this way. The person after you could not speak properly. This guy was also too late for the autograph but apparently, even his need will be addressed and he will be helped by this “important” head of an “important” ministry. So this person with the impediment needs to be taught the word of God and he needs to be taught how to speak the word of God in such a way that the word of God causes his “healing”. It is a fact that people who know the true word of God, can change their future and bring restoration in all areas of their lives because they act on the word of God, specifically by speaking correctly. They become victorious in all areas of life through their testimony and the life that they speak into their own lives.