Agriculture Secretary Sonny Perdue has been named the "designated survivor" during the State of the Union speech by U.S. President Donald Trump.
Each year, one member of the president's Cabinet is whisked away to an undisclosed location during the address in case a catastrophic event occurs and wipes out the line of presidential succession.
The tradition harkens back to the dawn of the Cold War, amid fears of a nuclear exchange with the Soviet Union.
After the vice president, the speaker of the House, and the president pro tempore of the Senate, the line of succession goes to Cabinet secretaries in the order they were created, beginning with the Secretary of State and ending with the Secretary of Homeland Security.
One member of Trump's Cabinet cannot serve as a designated survivor: Secretary of Transportation Elaine Chao, who was born in Taiwan and does not meet the constitutional requirements to serve as president.
The designated survivor will take over duties as the acting commander-in-chief is case of a catastrophic event.
美国农业部长珀杜是川普总统发表国情咨文期间的“指定幸存者”。
每年总统发表国情咨文时，为了避免灾难事件发生造成总统继任者无一幸免的情况发生，内阁中总会有一名部长担任 “指定幸存者”，被送到一个不向外界披露的地点。
这项传统始于冷战初期，当时人们担心与苏联爆发核战争。
根据美国法律，如果总统发生意外，继任总统的顺序为副总统、众议院议长、参议院议长，然后是内阁部长。内阁部长中的顺序按照各部成立时间，第一位是国务卿，最后一位是国土安全部长。
川普总统内阁中有一名部长不能做“指定幸存者”。按照美国宪法，在台湾出生的运输部长赵小兰没有担任总统的资格。
如若总统发表国情咨文期间发生灾难事件，“指定幸存者”将作为代总统接管一切权力。