Senator Chris Murphy said this week that as long as he's been in the Senate, he's never seen anything like the letter that Republicans recently wrote to Iranian leaders. He called the move by 47 GOP lawmakers "unprecedented."

"There's no doubt that part of our job is to weigh in on foreign policy. Part of what I do every day is speak to foreign leaders," he told WNPR's Where We Live. "So, there's nothing wrong with having a conversation with a foreign leader. But for virtually the entire Republican caucus to send a letter to the Ayatollah telling him that he shouldn't trust the President of the United States, notwithstanding the details of the negotiation, is really crossing a line in my opinion."

Murphy said that the Republicans were acting to "undermine" the President without any real information about the nuclear deal he's negotiating with Iran. Murphy said that he hasn't spoken with Republican Arizona Senator John McCain about the letter, which surfaced earlier this week when McCain was in Hartford meeting with Murphy to talk about Ukraine. Murphy said he believes McCain may have "re-thought" his decision to sign the letter.