The 47 members of Congress who signed the threatening letter to Iran went beyond the scope of their position and have brought shame and humiliation to the US, its President and its people. Because of their ignorance and arrogance, they may have jeopardized serious international negotiations which may result in a loss of life, American, Iranian and Israeli.
The U.S. Senate disciplines senators through formal censure or expulsion. Expulsion requires a two-thirds vote; censure requires a majority vote. Censure is a formal statement of disapproval and is less severe than expulsion but it remains as a permanent stain on the members record.
The House of Representatives offers only censure but the member must face a stinging rebuke on the House floor; itself a form of public humiliation.