In response to the rejection of legal immigration demonstrated by the policy efforts of the Trump administration, some economic analysts argue that the rejection of legal immigration harms the business of America in the long run. These analysts believe that the rejection of legal immigration causes three major challenges and threats to American economic and business development, including decreased labor force, reduced business activities, and decreased innovation activities. First, the rejection of legal immigration directly harms American business, because it is detrimental to the supply of labor force from legal immigrants. According to professor Borjas (2011), legal immigration has constituted a major source of labor force for American economy, because legal immigrants settling in America are mainly concerned with seeking better job opportunities. Legal immigrants provide numerous labor forces for American business and economy compared to white citizens. Meanwhile, immigrants are also willing to move to other places and work in harder conditions, which makes them an integral part of American business. Compared to legal immigrants, American whites are more focused on working in places near their homelands and in comfortable conditions. Thus, business in remote places and business noted for harder working conditions are mainly performed by legal immigrants. The rejection of legal immigration can harm American economy and business in an overall mode, because it harms the supply of adequate labor force for American economy and business development. As America steps into an aging society with white Americans lacking stimulations in bearing children, American economy and business have been exposed to great challenges and threats from the lack of labor force. Legal immigration provides an effective solution to these challenges through introducing an adequate labor force. Therefore, the rejection of legal immigration threatens the labor force supplied by legal immigrants, which harms the economic and business potentials of the Untied States.