Looking back on the prominent place Ted Kennedy occupied in contemporary American politics, it is important to make some distinctions between him and his two older brothers. Because to view them as an undifferentiated triumvirate like the Three Musketeers ignores a generation gap of monumental size that separated Kennedy from his martyred siblings. It was a chasm that presented him with a political environment far different from the one that confronted the older ones.

(In Hyannis Port, Mass.: President Kennedy, Attorney General Robert Kennedy and Sen. Ted Kennedy at home. Ted Kennedy, who passed away Tuesday, is the last of the three to die./AP file photo)

John and, to a lesser degree, Robert were products of World War II. Far too young to have served in that...