Designated successors are required to be natural-born citizens, at least 35 years old, and a resident of the United States for at least 14 years — the constitutional requirements to become president. Because of these requirements, officials are occasionally skipped — like former Secretary of State Madeline Albright, who immigrated from Czechoslovakia. In 2012, Agriculture Secretary Tom VilsackThomas J. VilsackUSDA: Farm-to-school programs help schools serve healthier meals OVERNIGHT MONEY: House poised to pass debt-ceiling bill MORE was the Cabinet's designated survivor.
Chu, a Nobel-prize winning physicist, announced earlier this month he was stepping down from the administration, although is expected to remain at least through the end of the month.
At the time, Chu said in a statement he was eager to return to California and "an academic life of teaching and research."
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