Does the President have Plenary Authority?

I am writing as your constituent to express my concern about recent statements regarding presidential authority and to seek your perspective on this critical constitutional matter. In a recent CNN appearance, Stephen Miller claimed that the President possesses "plenary authority." This assertion raises significant questions about the separation of powers enshrined in our Constitution—the very framework that defines the distinct roles of the Executive, Legislative, and Judicial branches. As someone who values our system of checks and balances, I am troubled by any suggestion that executive power is unlimited or unchecked. Our founders deliberately distributed power among three co-equal branches to prevent the concentration of authority and protect individual liberty. I would appreciate your thoughts on the following: 1. Do you believe the President possesses plenary authority as described by Mr. Miller? 2. How do you view the role of Congress in checking executive power, particularly when broad claims of authority are made? 3. What actions, if any, do you believe Congress should take to reaffirm its constitutional role in our system of government? I respectfully request a substantive response to these questions, as this issue goes to the heart of our democratic system. I look forward to understanding your position on this matter. Thank you for your service and attention to this concern.