Question: Ever since Harry Truman mocked the do-nothing Congress, our nation's representatives have been sensitive to charges that their time is spent only in pandering, politicking, and pot thumping.
Harry Truman made fun of Congress.

Answer: yes

Question: Even the grievances drawn up by the peasants and townspeople insisted on continuing devotion to the king himself.
The peasants and townspeople have grievances.

Answer: yes

Question: All that's missing ...
There are two things that are missing.

Answer:
it is not possible to tell