India, Feb. 25 -- One seat within the U.S. Capitol will remain vacant on Tuesday evening as President Donald Trump presents his State of the Union address.

The cabinet member who usually occupies this seat will be absent from the building and its vicinity while the rest of the government convenes for Trump's significant address to the nation. This person will watch the speech from a distance, symbolizing the doomsday president-in-waiting, a designation commonly referred to as the "designated survivor."

A designated survivor is chosen to guarantee that an individual in the line of leadership succession remains alive in the event of a catastrophic occurrence that eliminates everyone else. This concept originated during the Cold War and wa...