America's founding fathers decided to the powers of government among three branches to ensure that each would check and the actions of the others.

As the of the armed forces, the president fills a leading role in matters of national .
In order to allow a Supreme Court to decide cases fairly without having to worry about re-election, the founders chose to create lifetime for the position.

separate
justice
terms
defense
commander-in-chief
balance

separate the powers of government among three branches to ensure that each would check and balance the actions of the others.

As the commander-in-chief of the armed forces, the president fills a leading role in matters of national defense.
In order to allow a Supreme Court justice to decide cases fairly without having to worry about re-election, the founders chose to create lifetime terms for the position.