Members of the U.S. Postal Service’s board of governors risked losing their jobs if the agency persevered with ending Saturday mail delivery following passage of a final fiscal 2013 spending bill. That was the warning delivered by an outside law firm April 5–four days before the board pulled the plug on the plan. Proceeding with five-day mail delivery “would entail a number of risks,” Jeffrey Bucholtz,  a partner with King & Spalding, wrote in a 17-page opinion prepared for the Postal Service’s legal department. “First, violating a federal law would likely supply cause for the President to remove the Governors.”…