In Wealth of Nations, Adam Smith argued for a market system beyond the mercantilism of the day.
Before Adam Smith, the world thought of the world economy as a fixed pie. Countries would fight for dominance on slices of the pie. As a result, Government controlled much of the market.
Adam Smith came in and argued in Wealth of Nations for a free market wherein individuals would work to further their own interests, allowing the markets to grow.
The supremacy clause of the U.S. Constitution has supported the "<span>national government's sovereignty over matters related to citizen health care and education" since these can technically be decided at the state level as well, as opposed to interstate commerce and foreign policy, which can only be handled at the federal level. </span>
Mostly because they want juries to be fair to ensure a fair trial and that justice prevails. Someone without good moral character cannot be counted on to do the right thing.