called it a message that is dangerous. the decision to undercut our president and circumvent our constitutional system offends me as a matter of principle. two of the republican senators who signed the letter are basically standing their ground right now. they say an agreement with iran poses such a threat that it requires an unusual response. listen. >> the konsconstitution requires any treaty reached requires ratification by the senate. but president obama has defied the law and the constitution. this iran deal i believe, is a historic mistake. i believe it endangers the national security of this country. >> this is an unusual moment with an incredible risk to the world and our region and it required an unusual method to deal with it. i would send another one tomorrow. the risk of a nuclear iran is so great, that we need to do everything possible to keep us from minding ourselves in the