If Japan *did* become the 51st state, the State of Japan would get more than twice as many electoral votes as California, and would thus quickly come to dominate all presidential elections, as well as the House of Representatives. Demagogues like Tokyo mayor Shintaro Ishihara and incompetents like Prime Ministers Yukio Hatoyama and Yoshiro Mori would become major US political figures.
Right, but if they become 47 states, they will dominate the senate by adding 94 new senators. I don't think that solves the problem.
"An idealist is one who, on noticing that a rose smells better than a cabbage, concludes that it will also make better soup." - H.L. Mencken