Answer:
Natural rights and popular sovereignty
Explanation:
In relation to democracy, natural rights are each individual person's right to life, liberty, and the pursuit of happiness (if based on Thomas Jefferson's ideals, life liberty and property if based on John Locke's ideals) which are pretty important as they give each person their indivudual freedoms. Poplar sovereugnty basically means that elected representatives get their power from the consent of the people, which most modern day democracys rely on to stay functioning effectively.
Because they should know if the thing they are studying is like from or about or how it was made
John Marshall strengthened the Supreme Court’s Power by invoking judicial review in the case of Marbury v Madison.
Richard went gallently off to war, leaving his brother, an incompetent ruler, in his stead. John was so bad that the Magna Carter was signed on his watch. That was helpful because it took some of the monarch's power away. It didn't help everyone since it only gave rights to some of the nobility, but it was a start.
That was one effect of the crusades in England. Richard the Lionhearted likely would have had the same difficulties that John had to cope with. Richard was not a great politician (he put rebellions down with force), but he was a very gifted military technician. John faced the problem of having not much of an army to resist those wanting him to sign the Magna Carta. That should get you started.