The message that members of Congress ought to take away from the polls is that as far as public opinion is concerned, members have ample space to make a principled decision about the nuclear agreement. They do not have to fight against some well-entrenched public view. They will not suffer a backlash of public opinion—genuine public opinion—if they do their own part in educating the public and explaining the reasons for their position.

A gold standard for such education and explanation was set by Representative Jerrold Nadler, the New York Democrat who last week accompanied his announcement of support for the agreement with a remarkably thorough 5,200-word statement giving the reasons for his decision. The statement is one of the most insightful analyses of the relevant issues to come out of Congress or anywhere else, and it is very useful reading for any citizen looking for guidance and education on the subject. Not every member of Congress can be expected to be as thorough and diligent as Nadler has been, but he has shown what can be done along this line.

Members who come out differently are not necessarily intellectually lazy or incapable of understanding the relevant issues—and most of them aren't—nor are they misreading the public opinion polls. But they are being subjected to pressures that involve the role of money in politics, the Citizens United decision, and related matters that go beyond the direct influence being exerted on the Iran nuclear issue. This gets into reasons why even on some issues on which the American public does have a firm and reasonably well-informed prevailing view, such as Social Security, there still are significant political forces pushing in a different direction. It is for those general reasons, as well as the more specific sources of opposition to the Iranian nuclear agreement, that some members of Congress are exhibiting profiles in lack of courage. They are missing a good opportunity to show real leadership of the American public.