Lately the subject of intense criticism over the Madoff scam and the financial crisis, the chairman left on Tuesday. On Wednesday evening, President Obama named Elisse Walter as acting chair.

Yesterday, Barack Obama's inauguration day, Christopher Cox stepped down as the chairperson of the Securities and Exchange Commission after more than three and a half years on the job. On Wednesday evening, the president named Elisse Walter, the senior Democrat on the commission, as acting chairperson.

Cox, of late the subject of intense criticism for the agency's apparent inability to detect Bernard Madoff's Ponzi scheme as well as for alleged SEC failures related to the financial crisis, left quietly on Tuesday. He "sent an E-mail to the staff a week and a half ago saying that that would be his last day," John Nester, the commission's director of the office of public affairs, told

Indeed, on September 18, 2008, when then-presidential candidate Sen. John McCain called for Cox to be fired because of what McCain saw as the SEC's failure to control speculators, the SEC issued a release in which Cox defended the commission's record and said, "I have long made clear my intention to leave the SEC after the end of this Administration."

Following the commission's normal procedure on the departure of a chairperson, Cox left without the issuance of a press release. With Mary Schapiro, the president's nominee to head the commission, yet to be confirmed, the president followed the usual procedure and named Walter as acting chair.

Cox, a former Republican congressman, was named the 28th SEC chairperson by President Bush on June 2, 2005, and unanimously confirmed by the Senate on July 29, 2005. He was sworn in on August 3, 2005. During his tenure, the installation of XBRL data tagging and the move to international financial reporting standards were high priorities on his corporate agenda. He was also associated with SEC moves to make compliance with internal controls standards under the Sarbanes-Oxley law easier on smaller public companies.

In Congress, Cox served as chairman of the House Policy Committee; chairman of the Committee on Homeland Security; chairman of the Select Committee on U.S. National Security; chairman of the Select Committee on Homeland Security (the predecessor to the permanent House Committee); chairman of the Task Force on Capital Markets; and chairman of the Task Force on Budget Process Reform.