What does "the changing face of the United States" mean?

What will be an ideal response?

Answer: Starting in the 1980s, new immigration into the United States primarily came from Latin America and Asia. In 1990, three out of four U.S. residents were of white European ancestry. By the middle of the 21st century, that ratio will drop to only one out of two. The Hispanic market is the fastest growing sector of the U.S. economy. It is a market that has been, for many years, underrated.