Several readers, plus my raised-in-Japan Atlantic colleague James Gibney, have reminded me that Barack Obama is not the first American president whose name has been converted into an ordinary word in Japanese. After the first President Bush fell ill and vomited on Japanese Prime Minister Miyazawa at a state dinner in Tokyo in 1992, the term Bushu-suru -- ブッシュする, "do a Bush" -- became a joke staple of Japanese slang. Bush understood how Montezuma must have felt about having his name appropriated for gastrointestinal use.
Via Google Books, an account from the Encyclopedia of Political Communication of the meaning of Bushu-suru, though I prefer my own "do a Bush" English version.
I don't know whether doing "a Clinton" -- クリントンする -- came to mean anything in Japanese.