Each elector must cast distinct votes for the president and the vice president and can't cast two votes. The Senate must choose between the candidates with the two highest numbers.
Amendment 20
Amendment 20 is an amendment to the constitution that sets the inauguration date for the president and new sessions for congress.
This amendment prevents presidents already elected twice from being elected again
Amendment 22
Poll tax is no longer required in the voting process
Amendment 24
Amendment 25
The vice president becomes president if the main president dies or resigns.