What is the rank of a US senator and why can he challenge the president?

This is that you don't know much about the American political system. Never use the thinking of China people to understand the United States, or you will be puzzled. There is a good joke. If the governor of Rhode Island (the smallest state in the United States) is in a hurry and sees the president of the United States in the public toilet, he will kick him out and go in first. The reason is that the governor is elected by the people and the president is elected by the people. They are all responsible to their own voters, so there is no difference between scale and management. Moreover, the United States is a federal system, and the governor has great power and his influence in the state is far stronger than that of the president. Many Americans. This is a very different place from China. China's administrative level is severe. Older than yourself, you have to be condescending. In the United States, there is decentralization, and local power and people's power are great. In China, there is centralization, and the central government or the superior has great power. These are two completely different systems.