You mean how the child of an immigrant is President?
The president's father was never an immigrant. An immigrant is someone who comes to life permanently in a new country. He was a foreign student with a wife in Kenya and eventually returned to Kenya with an American third wife upon the completion of his studies.
Several presidents have been a child of an immigrant: Thomas Jefferson, Andrew Jackson, James Buchanan, Chester Arthur, Woodrow Wilson and Herbert Hoover.
US immigration goes beyond just the President's personal views and desires. The present situation is pretty difficult for many would-be immigrants, even those from middle class backgrounds in stable countries. If they lack a degree or their degree isn't recognized, they can't easily get a work visa (for permanent resident status, not temporary workers). They have to get married, go for the diversity visa program, or become a student (may be their second or third degree for some if they go this route).
This is true. But compare it to other countries: even where immigration is more relaxed, the cultural acceptance of foreign culture is greater in the US than most places. The only place I might prefer to be as a foreigner would be Canada.
Mary Anne MacLeod Trump, mother to Donald, was born on the Isle of Lewis in Scotland in 1912, emigrated to the US in 1930, married an American in 1936, naturalized 1942.
