Japan is a Trumpian paradise of low immigration rates. It’s also a dying country. Japan's prime minister, Shinzo Abe, at a plenary session of the lower house of parliament on Aug. 1 in Tokyo. (Tomohiro Ohsumi/Getty) KITAKYUSHU, Japan — For a sense of what the United States might look like in a reality where the hard right’s dreams of drastically reduced immigration come true, you could come to Jap