Describe the powers of the legislative, executive, and judicial branches and explain how checks and balances -- including judicial review -- keep any one branch from becoming too powerful.
The Constitution's framers, influenced by the French philosopher Montesquieu, split the national government into three branches so no single part could grow too powerful -- exactly the fear that drove the whole Convention. Article I creates the legislative branch, Congress, which makes laws. Article II creates the executive branch, headed by the President, who enforces laws and leads the military and foreign policy. Article III creates the judicial branch, the courts, which interpret laws and settle disputes under them.
Each branch can check the others. Congress passes laws, but the President can veto them; Congress can override a veto with a two-thirds vote in both houses. The President appoints judges and Cabinet officials, but the Senate must approve them. Courts can rule laws unconstitutional -- a power called judicial review that is not written explicitly in the Constitution but was established in the 1803 Supreme Court case Marbury v. Madison, when Chief Justice John Marshall ruled that the Court had the authority to strike down a law that conflicted with the Constitution. Since then, judicial review has been one of the most important checks in the whole system.
Mastery looks like: They can trace a bill through all three branches, correctly identifying which branch checks which at each step, including judicial review.
Common stumbles: Listing the three branches correctly but not being able to explain a specific CHECK one branch has on another.