Have you ever wondered why so many politicians refer to citizens of this country as "taxpayers?" I do more as a citizen of the United States than pay taxes. I vote. I serve on a jury when asked. I obey laws. When did paying taxes become, as Jill Lepore wrote in a fine piece on taxation in the Nov. 26 New Yorker magazine, "the defining act of citizenship?" According to Lepore, the first time Americans were referred to as taxpayers was during a 1938 campaign mounted by business lobbies to repeal the 16th amendment to the U.S. Constitution, the one …