Which of the following is considered a non-legislative power of Congress?

The power to impeach officials is classified as a non-legislative power of Congress because it relates to the oversight and removal of government officials rather than the creation of laws. Impeachment is a check on the executive branch, allowing Congress to remove a president or other federal officials who commit "high crimes and misdemeanors." It involves a specific process where the House of Representatives has the exclusive authority to bring charges (impeach), while the Senate holds the trial and determines whether to convict and remove the official.

In contrast, declaring war, making treaties, and regulating commerce are considered legislative powers, as they involve creating rules and regulations that govern the nation and its interactions, both domestically and internationally. These powers are directly tied to Congress's role in shaping laws and policies. Thus, impeachment stands out as it does not involve the legislative process of lawmaking but focuses on holding officials accountable for their actions.