Final answer:
The Senate has the power to approve or reject treaties made by the president, which serves as a check on the president's authority in foreign policy.
Step-by-step explanation:
One power unique to the Senate is the power to approve or reject treaties made by the president. The framers gave the Senate this power to ensure that the president does not have unchecked authority in conducting foreign policy. By requiring Senate approval, it provides a system of checks and balances and ensures that a broader range of perspectives are considered in making important decisions.
Learn more about Powers of the Senate and the reasons behind them