If this is such a good idea, why has Congress voted it down in the past?

A simple majority of both houses of congress voted in favor of the amendment in 1990 and the House of Representatives passed the amendment in 1995, 1997, 1999, 2001, 2003 and 2005, each time by a super-majority of two-thirds. Today, the Citizens Flag Alliance has teams working in every state to raise public awareness of this issue and to encourage citizens to contact their members of Congress and express their desire for a constitutional amendment. It has failed by the narrowest margin (one vote) in the Senate, because it became politicized.