One of the country’s most powerful business groups is spearheading a new front in the pharmaceutical industry’s efforts to undo the U.S. government’s powers to negotiate drug prices.  On Friday, the U.S. Chamber of Commerce filed a lawsuit in U.S. District Court in Dayton, Ohio, arguing that the price-negotiation program is unconstitutional, violating due process and other protections. The lawsuit comes just days after pharmaceutical giant Merck & Co. filed a similar federal lawsuit on Tuesday.