President Trump demands Apple to start making iPhones in the U.S. or pay tariffs on imported iPhones.Apple has shifted production to various Asian countries but not the U.S., with 80% of iPhones still made in China.Making iPhones in the U.S. would be expensive and require doubling prices due to higher costs and smaller population.Experts say shifting iPhone production to the U.S. now would be economically unfeasible, especially with potential changes in technology.