Director of Enforcement Agency Resigns to Work for Bank John T. Morton, the director of Immigration and Customs Enforcement, the Department of Homeland Security agency in charge of controlling illegal immigration, announced Monday that he was stepping down after four years to work for a private bank. Mladen Antonov/Agence France-Presse - Getty Images John T. Morton had many critics. The resignation of Mr. Morton, who led the agency through multiple political battles over federal immigration enforcement policy, had been expected and was not forced, Homeland Security officials said. But it opened up the possibility of a Senate confirmation hearing for his successor that could become a report card on the Obama administration's enforcement efforts amid the tense debate in Congress over legislation to overhaul the immigration system. Mr. Morton was responsible for changing the direction of the agency, known as ICE, and its 20,000 employees, by refocusing on deporting convicted criminals and serial visa violators, while steering away from undocumented immigrants who did not have criminal records. Aside from the White House and Janet Napolitano, the homeland security secretary, that shift in policy had few enthusiastic defenders. On Monday, Ms. Napolitano praised Mr. Morton, saying he "oversaw ICE's use of prosecutorial discretion, recognizing that ICE agents and officers can best impact public safety by focusing on those individuals who pose a threat." Immigrant advocate groups denounced Mr. Morton for setting a record for deportations, with more than 1.4 million deported in four years. Chris Newman, the legal director of the National Day Laborer Organizing Network, one of those organizations, called Mr. Morton's departure "great news." Mr. Morton also faced a rebellion from within his own ranks, with the union of deportation agents protesting that the prosecutorial discretion policy was restraining them from doing their jobs. Chris Crane, the leader of that union, filed a lawsuit against Ms. Napolitano to stop the policy. Opponents of a bipartisan immigration bill before the Senate have taken up the complaints of the deportation agents to argue that the Obama administration is not prepared to prevent a new wave of illegal immigration if Congress opens a pathway to citizenship for immigrants already here illegally. Mr. Morton will step down in July to become a senior vice president of Capital One, a bank with headquarters in Virginia.