WASHINGTON — Before we explore the problems with the permanent exhibition that opened this month at the National Archives here, it might help to recognize the challenges it faced. The exhibition, “Records of Rights,” is the first attraction you see after passing through the building’s new marble-clad entrance. It is meant to prepare a million visitors a year for what awaits them above, in the dimly lit Rotunda: original copies of the Declaration of Independence, the Constitution and the Bill of Rights — founding documents with such a sacral stature, they are viewed in near silence. What kind of exhibition could possibly serve as preamble?

At first, it seems an answer had been found: You see the eerie yellow glow of a display case. And inside, written on thick vellum, with a threaded ribbon holding an ancient royal seal, is one of four surviving copies of the 1297 Magna Carta, a contract between English barons and their tyrannical king.

What a way to begin this exhibition while also foreshadowing prospects ahead! The document was purchased by the investor and philanthropist David M. Rubenstein in 2007 for $21.3 million; he provided it on permanent loan. He also donated a major portion of the $30 million required for the new entrance plaza, the new gallery we are entering, and the exhibition that opens with this document....