So how did the previously obscure term tax inversions become part of Washington parlance, fodder for the next presidential campaign and the issue that helped derail a U.S. Treasury nominee? Thank, or blame, depending on your perspective, cutting-edge tax lawyers, populist Democrats, a banana seller, a drugmaker, a hamburger chain, the 35 percent U.S. corporate tax rate, and a Wall Street banker named Antonio Weiss. There is also the prospect that inversions could cost the U.S. Treasury up to $33.6 billion in lost revenue over the next decade, according to the congressional Joint Committee on Taxation.