Sens. Kent Conrad (D-N.D.) and Mike Crapo (R-Idaho) introduced the bill in April. Conrad said the bill was a response to one of his constituents, who asked for help getting rid of the word "lunatic," language that Conrad agreed is "inappropriate" to have in U.S. law, given the modern understanding of mental illness.
The word "lunatic" appears in Title 1, Chapter 1 of the U.S. Code, which covers rules of construction. Chapter 1 holds that when determining the meaning of any law, "the words 'insane' and 'insane person' and 'lunatic' shall include every idiot, lunatic, insane person and person non compos mentis."
According to Conrad's bill, the word also appears in laws related to banking that deal with the authority to take receivership of estates.