Final answer:
The 'lame duck' amendment is the Twentieth Amendment to the United States Constitution, ratified in 1933 to reduce the time between presidential election and inauguration.
Step-by-step explanation:
The constitutional amendment known as the 'lame duck' amendment is the Twentieth Amendment to the United States Constitution.
It was ratified in 1933 and its purpose was to shorten the period of time between presidential election and inauguration.
By moving the inauguration from March 4th to January 20th, the amendment sought to reduce the amount of time when a president who was not reelected could still hold power but lacked the political mandate that comes with being elected.
Learn more about Twentieth Amendment to the United States Constitution