Final answer:
The ultimate limit on the POTUS is the system of checks and balances, which prevents any one branch of government from having too much power. The President's power is checked by the judicial and legislative branches.
Step-by-step explanation:
The ultimate limit or check on the POTUS is the concept of checks and balances within the United States government. This system ensures that no single branch of government has too much power. For example, the President's power is checked by the judicial branch, which can declare presidential actions as unconstitutional. Additionally, the legislative branch has the power to impeach and remove a president from office if they commit acts deemed as high crimes and misdemeanors.
Learn more about The ultimate limit or check on the POTUS