Former New Jersey governor and U.S. Sen. Jon Corzine, whom President Obama once hailed as an “honorable man” and one of his “best partners” in the White House, has been subpoenaed to testify before Congress about his role in the collapse of the investment firm MF Global. Corzine was chairman and CEO of the company between March 2010 and Oct. 31, 2011, when it filed for bankruptcy. An estimated $1.2 billion has not been accounted for, leaving many investor accounts drained. The FBI and Justice Department are also investigating the case. The unanimous, bipartisan vote today to require Corzine to...