What are two reasons why the Chinese exclusion act of 1892 was passed?

The Chinese Exclusion Act was the product of a wide anti-chinese movement at the end of the 19th century as americans started to see chinese people as competition for jobs and wages. Another reason for the government to pass the act was the growing concern about maintaining white racial purity, despite the fact that the chinese only made a very small percantage of the population at the time.