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WASHINGTON — Janet Napolitano, the secretary of homeland security, announced Friday that she was stepping down, setting off a search to fill one of the most challenging positions in government at a time when the Obama administration is struggling to get a team in place for the president’s second term.
Napolitano, a former Arizona governor who for 4½ years shaped the administration’s response to hurricanes, terrorist attacks, illegal immigration, and a catastrophic oil spill, will leave in September to become president of the University of California system. Napolitano had her eye on becoming the next attorney general but now is taking herself out of the Washington arena.