The 1960 book ends with Chapter 8. The chapters that follow were written at different times between 1960 and the publication of the 1990 edition, thus encompassing interim editions.

Chapter 9 is the first of the five chapters written after Presidential Power was published in 1960. The chapter, written in 1968, offers a framework for appraising the performance of a president and then, with a major caveat, applies the framework to the presidency of John F. Kennedy.

Neustadt worked in the Kennedy administration, and his positive regard for the slain president comes through in nostalgic language that is otherwise out of character for this author.

In Chapter 10 Neustadt re-evaluates the whole argument of the 1960 book, primarily through the through the prism of the Johnson and Nixon presidencies. Written in 1976, the chapter expresses some of the disenchantment that followed President Nixon’s resignation and acknowledges significant changes affecting the demands and responsibilities on the president. However, it ultimately offers a strong endorsement of the basic conclusion and recommendations in the 1960 book.

This chapter, the longest of the entire book, notes that before his presidency, Woodrow Wilson wrote two scholarly works approximately 15 years apart and, in the later work, acknowledged major changes in the significance of the presidency that forced re-evaluation of his conclusions.