Answer:
The Constitution of the United States is designed to prevent tyranny because it has several dispositions that have been effective in achieving so, mainly, dispositions related with the structure of government, in which the government is split between three powers: the executive, the legislative, and the judiciary, each with checks and balances, and in the federalist nature of government, giving the federal government only those powers that are specifically given to it in the Constitution, and the rest being left to the states.
It could be improved by addressing the overreach of the executive power in recent decades, meaning that the president has become more and more powerful. This could be done by giving more powers to Congress, or by removing some powers from the presidency, or both.
