Whatever else "Born Yesterday" may have to offer above the general level of prefabricated comedy (and I am one who thinks it hasn't very much), Garson Kanin's play contains a wonderfully engaging study of a young woman in the throes of a belated literary and political education. The pattern of her development—from a cheerful moral vacuum like the one in "Gentlemen Prefer Blondes" to a state that almost seems to prophesy another congresswoman from Connecticut—is not quite new to art…. [The heroine here], however, undergoes an even more astounding change than any of her predecessors and she is drawn in fascinating detail.

In the beginning, Mr. Kanin's girl … is shown with her protector, one Harry Brock, in a hotel in Washington, where he has come to buy enough senators to set up a cartel in scrap metal…. The lines and the philosophy provided for her by...