In The Absolutely True Diary of a Part-time Indian, white people are important to Junior because they are a barrier that he must continually face. In the novel, Junior realizes that he is receiving a bad education on the reservation, so he decides that he wants to go to a better school. This appears to be a simple decision; however, the school that Junior has to go to is made up of only white students. Because he is Indian, Junior will be forced to deal with being a minority in his new school.
Beyond the everyday struggles that Junior has to go through, Junior also realizes that racial and cultural boundaries are institutionalized, and many on the reservation are angry because they are lied to by the government which is characterized as "white" or controlling. Because white people have such an influence on Junior's life, they are important to him.