Even before today's tragic shooting in San Bernardino, pressure was building in Washington to overturn an NRA-backed amendment that has barred federal research on gun violence for nearly 20 years. More than 2,000 physicians, dozens of Democratic lawmakers, and even the author of the amendment have all called on Congress to once again allow gun violence to be investigated as a public health issue. On Wednesday, nine medical associations publicly urged Congress to overturn the so-called Dickey Amendment, which in 1996 effectively halted research by the Centers for Disease Control and Prevention (CDC) and the National Institutes of Health (NIH) into the causes of gun violence. "Gun violence is a public health problem that kills 90 Americans a day," Dr.