Breaking Down the Line of Succession to Replace US Presidents and VPs

Here's who takes over if both the president and vice president are unavailable.

— -- The vice presidential debate this week highlighted the backup role to commander in chief, but there's a line of succession to the powers and duties that goes well beyond that.

The Founding Fathers initially struggled with developing the order for who would take over in the case of catastrophe, but Congress eventually solidified the chain in 1972 with the first version of the Presidential Succession Act.

The speaker of the House is after the vice president, followed by the pro tempore of the U.S. Senate and secretaries of state, treasury and defense, in that order.

Learn the rationale for the sequence and more facts about the designated-survivor system in the video above.