Federalism is the U.S. system where power is split between the national government and the states. The Constitution gives enumerated (express) powers to the national government and allows implied powers via the Necessary and Proper Clause; states keep reserved powers under the 10th Amendment. Some powers are concurrent—both levels can tax, make laws, and build roads. That split creates ongoing debates about who should act on issues like education, drugs, or disaster response. The national government uses tools—categorical grants (tight rules), block grants (fewer rules), revenue sharing (rare), and mandates—to influence state policy. Key examples include the National Minimum Drinking Age Act and state marijuana legalization; court cases about the Commerce Clause (Lopez vs. earlier New Deal cases) also shift the balance. For AP exam prep, focus on LO 1.7.A concepts and how exclusive, concurrent, and reserved powers affect society. Review the Topic 1.7 study guide (https://library.fiveable.me/ap-us-government/unit-1/relationship-between-states-federal-government/study-guide/kp9bW6CAUn0T0GiGqDUO) and try practice questions (https://library.fiveable.me/practice/ap-us-government).

They clash because the Constitution creates federalism—two levels of government sharing authority—so there's always gray area about who controls what. The national government has enumerated (and some implied via the Necessary and Proper Clause) powers, while the Tenth Amendment reserves all other powers to the states. Concurrent powers (like taxing or making laws) overlap, which invites conflict. Money and policy tools deepen disputes: the federal government uses categorical grants, block grants, revenue sharing, and mandates to influence state action, and states push back to protect their reserved powers (think marijuana legalization or education spending). Court cases and changing political priorities (New Deal expansion vs. the 1980s devolution push) also shift the balance over time. For AP prep, understand these terms and examples and practice SCOTUS/comparison questions—see the Topic 1.7 study guide (https://library.fiveable.me/ap-us-government/unit-1/relationship-between-states-federal-government/study-guide/kp9bW6CAUn0T0GiGqDUO) and unit review (https://library.fiveable.me/ap-us-government/unit-1). For extra practice, try the 1,000+ AP questions (https://library.fiveable.me/practice/ap-us-government).

Exclusive powers: powers held by only one level of government. For the national government that includes enumerated powers in the Constitution (like declaring war, coining money) and implied powers under the Necessary and Proper Clause. States have some exclusive powers too (e.g., organizing local governments in many cases). Concurrent powers: powers both national and state governments can exercise at the same time—examples from the CED are taxing, making and enforcing laws, and building roads. Both can act, but federal law can preempt state law under the Supremacy Clause. Reserved powers: powers not delegated to the national government nor prohibited to the states, reserved to the states by the Tenth Amendment—things like running public schools, regulating intrastate commerce, licensing. For AP prep, know these CED terms (enumerated, implied, Tenth Amendment, concurrent) and be ready to apply them on multiple-choice and FRQ prompts. Review the Topic 1.7 study guide on Fiveable (https://library.fiveable.me/ap-us-government/unit-1/relationship-between-states-federal-government/study-guide/kp9bW6CAUn0T0GiGqDUO) and practice questions (https://library.fiveable.me/practice/ap-us-government).

Enumerated powers are the specific authorities the Constitution gives Congress (they’re written down). Examples: declaring war, coining money, regulating interstate commerce. Implied powers aren’t listed word-for-word but are “inferred” from an enumerated power using the Necessary and Proper Clause—they let the national government carry out its constitutional duties. Classic example: Congress created the national bank (McCulloch v. Maryland) even though “bank” isn’t in the text; it was seen as necessary to exercise taxing/borrowing powers. Remember the flip side: the Tenth Amendment reserves powers not given to the national government to the states. On the AP exam this shows up under federalism (LO 1.7.A)—expect multiple-choice or FRQ questions asking you to compare exclusive, concurrent, reserved, enumerated, and implied powers. For a quick review, check the Topic 1.7 study guide (https://library.fiveable.me/ap-us-government/unit-1/relationship-between-states-federal-government/study-guide/kp9bW6CAUn0T0GiGqDUO) and practice more at (https://library.fiveable.me/practice/ap-us-government).

The Tenth Amendment says any power not given to the national government or denied to the states is “reserved to the states.” Practically that means states control things like police powers (public health, safety, welfare), regulate intrastate commerce, run elections, create local governments, oversee education, issue professional licenses, set family and criminal law details, and manage highways and land use. Some powers are concurrent (both can tax, make/enforce laws, build roads). States can’t contradict the Constitution or federal law (Supremacy Clause) and Congress can influence states with mandates or grants (categorical, block, revenue sharing). For AP exam framing: this maps to LO 1.7.A and EKs 1.7.A.1–1.7.A.4—know reserved vs. exclusive vs. concurrent powers and examples (e.g., marijuana legalization vs. federal drug law). Review the Topic 1.7 study guide (https://library.fiveable.me/ap-us-government/unit-1/relationship-between-states-federal-government/study-guide/kp9bW6CAUn0T0GiGqDUO) and use practice problems (https://library.fiveable.me/practice/ap-us-government) to drill examples.

Categorical grants are federal funds for narrowly defined purposes (like Medicaid or school lunch programs) and come with strict rules about how money must be spent and reported. Block grants give federal money for broad purposes (like “community development” or “education”) with minimal restrictions so states can decide priorities. Because categorical grants expand federal control and are the most common tool for national policy, the national government prefers them; states prefer block grants because they preserve state authority and flexibility (aligned with the CED’s EK 1.7.A.5 points ii–iii). For AP exam study, tie this to LO 1.7.A and EK 1.7.A.5—you may be asked to explain how grant types show federalism’s balance of power (see the Topic 1.7 study guide on Fiveable: https://library.fiveable.me/ap-us-government/unit-1/relationship-between-states-federal-government/study-guide/kp9bW6CAUn0T0GiGqDUO). For extra practice, try problems at https://library.fiveable.me/practice/ap-us-government.

The National Minimum Drinking Age Act (1984) didn’t directly make a national drinking age—Congress used its spending power. It said states that didn’t raise the drinking age to 21 would lose a portion of federal highway funds (a conditional/categorical grant). In South Dakota v. Dole (1987) the Supreme Court upheld that use of Congress’s spending power, so the law was constitutional. Most states complied because refusing meant losing significant federal money for highways—a practical financial mandate that shifted power toward the national government while raising Tenth Amendment questions about reserved state powers. This is a classic example of federalism, conditional grants/mandates, and how the national government can influence state policy. For more on this topic, see the Topic 1.7 study guide (https://library.fiveable.me/ap-us-government/unit-1/relationship-between-states-federal-government/study-guide/kp9bW6CAUn0T0GiGqDUO) and practice questions (https://library.fiveable.me/practice/ap-us-government).

Because of federalism, states have “reserved powers” under the Tenth Amendment to make many local criminal and regulatory policies (EK 1.7.A.3). Marijuana remains illegal under federal law (a federal statute), but states like Colorado and Washington voted to legalize possession and regulation for personal use (2012). That creates a tension: the Supremacy Clause means federal law overrides state law, but the federal government must choose how to enforce its laws. In practice, federal prosecutors prioritize resources and sometimes defer to state systems (prosecutorial discretion), so state-legal markets operate without constant federal crackdowns. This is an example of concurrent/reserved powers and the ongoing balance between national authority and state autonomy (LO 1.7.A). For AP review, study how federal mandates, the commerce clause, and the Tenth Amendment shape these conflicts (see the Topic 1.7 study guide: https://library.fiveable.me/ap-us-government/unit-1/relationship-between-states-federal-government/study-guide/kp9bW6CAUn0T0GiGqDUO). For more practice, try questions at (https://library.fiveable.me/practice/ap-us-government).

Write a tight 3-step SAQ: (1) direct answer (thesis), (2) support with specific evidence, (3) brief explanation of how the evidence shows the balance of power. Example outline you can use (each part ≈1–2 sentences): 1) Thesis: “Federalism divides power between the national and state governments; the Tenth Amendment reserves non-delegated powers to states while the Commerce Clause and Necessary & Proper Clause expand federal authority.” (uses EK 1.7.A.2–1.7.A.3) 2) Evidence: give one specific example—e.g., National Minimum Drinking Age Act (conditional categorical grant/mandate) OR United States v. Lopez (limits on commerce-clause power) OR state marijuana legalization in Colorado (state resistance to federal policy). (use EKs 1.7.A.5 and keywords) 3) Explanation: explain how that example shifts the balance—grants/mandates increase federal leverage; Lopez shows a judicial check that preserves state power. Keep answers concise (1–3 sentences per part), use AP terms (enumerated, reserved, concurrent, categorical/block grants, mandates), and connect to LO 1.7.A. For more examples and practice SAQs, see the Topic 1.7 study guide (https://library.fiveable.me/ap-us-government/unit-1/relationship-between-states-federal-government/study-guide/kp9bW6CAUn0T0GiGqDUO) and try practice questions (https://library.fiveable.me/practice/ap-us-government).

The devolution revolution of the 1980s (associated with Reagan) shifted federalism toward giving states more power and responsibility. Practically, the national government favored block grants and revenue flexibility over categorical grants and direct programs, arguing for more state control under the Tenth Amendment idea of reserved powers. Effects: more state policy variation (greater experimentation), increased state responsibility for program funding (fiscal strain on some states), and a rhetorical/administrative move away from cooperative federalism toward competitive/dual elements. However, Congress still used federal mandates and conditional funding, so national influence didn’t vanish—the balance of power became more contested. For the AP exam, link these changes to grant types (block vs. categorical), mandates, and the debate over reserved powers (LO 1.7.A). For a targeted review, see the Topic 1.7 study guide (https://library.fiveable.me/ap-us-government/unit-1/relationship-between-states-federal-government/study-guide/kp9bW6CAUn0T0GiGqDUO) and practice questions (https://library.fiveable.me/practice/ap-us-government).

Hurricane Katrina is a classic example of federalism in action—and what can go wrong when coordination fails. States have primary responsibility for public safety and emergency response (reserved powers under the Tenth Amendment), so Louisiana and New Orleans led initial efforts. The national government has concurrent and implied powers to help—Congress authorized federal disaster relief and FEMA administers aid under the Stafford Act (a form of federal support/mandate and grants). In 2005, slow federal-state coordination, unclear chains of command, and disputes over who should act caused delays and finger-pointing, showing how shared (concurrent) responsibilities require clear roles and resources. For the AP exam, this ties to EK 1.7.A.1–A.5 (federalism, reserved/concurrent powers, grants/mandates) and is an illustrative example you should use when explaining the balance of power. Want a quick review? Check the Topic 1.7 study guide (https://library.fiveable.me/ap-us-government/unit-1/relationship-between-states-federal-government/study-guide/kp9bW6CAUn0T0GiGqDUO) and try practice questions (https://library.fiveable.me/practice/ap-us-government).

Unfunded mandates are federal requirements that force states (or localities) to do something—like expand Medicaid, meet clean-air rules, or run special education programs—without giving full federal funding to cover the cost. They’re an example of a federal mandate (CED: Topic 1.7, mandates). States hate them because they create financial burdens, reduce state discretion (conflicting with reserved powers under the Tenth Amendment), and can force trade-offs with other priorities—no new federal money, but new responsibilities. Politically, mandates can create tension over federalism: national goals vs. state control. For the AP exam, know mandates’ contrast with block grants, categorical grants, and revenue sharing (CED EK 1.7.A.5.i–iv). Want to review this topic? Check the Topic 1.7 study guide on Fiveable (https://library.fiveable.me/ap-us-government/unit-1/relationship-between-states-federal-government/study-guide/kp9bW6CAUn0T0GiGqDUO) and practice questions (https://library.fiveable.me/practice/ap-us-government).

The Necessary and Proper Clause (Article I, Section 8) gives Congress implied powers—authority not specifically listed but inferred as needed to carry out its enumerated powers. In practice, that means if the Constitution lets Congress regulate interstate commerce or raise an army, Congress can also pass laws “necessary and proper” to make those powers work (like creating agencies or regulations). Courts decide how broad “necessary and proper” is: some rulings (like NLRB v. Jones & Laughlin era) expanded federal power by linking many activities to interstate commerce; other decisions (like United States v. Lopez) put limits. For the AP exam, tie this to LO 1.7.A and EKs: implied powers from the Necessary and Proper Clause count as exclusive federal authority, shifting the federal–state balance against Tenth Amendment reserved powers. Want more practice on federalism concepts? Check the Topic 1.7 study guide (https://library.fiveable.me/ap-us-government/unit-1/relationship-between-states-federal-government/study-guide/kp9bW6CAUn0T0GiGqDUO) and practice questions (https://library.fiveable.me/practice/ap-us-government).

The New Deal shifted power toward the national government by expanding federal authority to regulate the economy and directly help citizens—moving the U.S. from mostly dual federalism toward cooperative federalism. Through New Deal laws (like the National Recovery Act) and supportive Supreme Court rulings in the mid-1930s, Congress used the Commerce Clause and implied powers to create regulatory agencies and programs (Social Security, NLRB) that set national standards and funded state implementation. That meant more categorical grants, mandates, and federal regulation—states still run programs but rely on federal money and rules. This change is exactly the kind of federalism shift described in LO 1.7.A (more national power via enumerated/implied powers, less strict state-only control; see the Topic 1.7 study guide (https://library.fiveable.me/ap-us-government/unit-1/relationship-between-states-federal-government/study-guide/kp9bW6CAUn0T0GiGqDUO)). For extra practice, use Fiveable’s unit study guides and practice questions (https://library.fiveable.me/practice/ap-us-government).

Revenue sharing and categorical grants are both ways the national government gives money to states, but they differ in how much control Washington keeps. Revenue sharing (rarely used) is basically federal funding with almost no restrictions—states can spend it however they want, so it preserves state discretion (CED EK 1.7.A.5.i). Categorical grants are money the national government gives for a specific category or purpose (like education or highway construction); they come with strict rules and often require state matching funds, so they let the federal government shape state policy and are the most common form of funding (CED EK 1.7.A.5.iii). Remember: block grants sit in between (fewer restrictions than categorical grants). Knowing these distinctions helps on FRQ prompts about federalism and the balance of power (Topic 1.7 study guide: https://library.fiveable.me/ap-us-government/unit-1/relationship-between-states-federal-government/study-guide/kp9bW6CAUn0T0GiGqDUO). For extra practice, check Fiveable’s Unit 1 review and 1000+ practice questions (https://library.fiveable.me/ap-us-government/unit-1; https://library.fiveable.me/practice/ap-us-government).