For the last few decades, thousands of foreign born students graduated from US Universities and left this country to start businesses in their own countries. This is the main reason why the US is lagging behind many other countries. The only reason why the US is still the biggest economy is because of its quantity NOT because of its quality.
So, to keep the quality of this country's economy healthier, we need to keep those foreign born students in the US, especially Undergraduate Degree holders because they spend at least 4 years in the US Universities and take number of courses which are linked to American society and American values. By doing this we will create more entrepreneurs in the future and will help this country to be on the top for more decades to come.