Because Confucianism was an ethical social, and political belief system, as opposed to a religion, it was compatible with other religions. In other words, a person could, for example, practice both Buddhism and Confucianism simultaneously, This flexibility enabled Confucianism to flourish. Government leaders, too embraced it, because it was intended to create an orderly society. Chinese culture in which communities became extremely tight-knit; members had duties and responsibilities to many others in the community from birth to death.
The congress are voted for by the people. If someone wants to run for Congress, they run against other people. The people choose who they want, and vote for them when the time comes.