An OPINION

Obama likened American, Republicans and Democrats who are in opposition to the Iran Treaty to the Iranian hardliners.
Our United States Constitution requires the President to be our Executive. Each of the Presidents since George Washington, as well as the elected and appointed Senators have taken their 'Oath of Office' wherein they swore to support and defend the Constitution; - against all enemies, foreign and domestic, with their pledge "So help me God".
This does not permit any President, or Senators, to be a self styled opponents of our Constitution. Article. II, provides the President with Executive Power. Executive power does not grant authority to pursue courses counter to our founding document/s.
Section .2. (of the same Article. II) requires the advice and consent of two thirds of the Senate regarding Treaties with foreign states or countries.
How can our Senators allow our commitment to a treaty with the Country whose principles are diametrically opposed to our founding principles as established in "Declaration of Independence", our "Constitutions Preamble" and the myriad of writings in our foundation? 
In my opinion any Senator and the President, who is in approval the latest Iran Agreement, should be subject to "Recall" because they are in opposition to their "Oath of Office".