Final answer:
The President is most likely to exercise their power to pardon during the lame-duck period.
Step-by-step explanation:
The power to pardon is most likely to be exercised by the President during the lame-duck period. This is the period of time between the election of a new President and the inauguration of the incoming President. During this time, a President may be more inclined to use their pardon power without fear of political backlash or impact on their own re-election. Examples of presidents using their power to pardon during the lame-duck period include President Gerald Ford pardoning Richard Nixon and President Donald Trump granting numerous pardons at the end of his presidency.