The Role of Congress: Checks and Balances Explained
Last updated: January 15, 2026
Congress plays a central role in the U.S. system of checks and balances, serving as the legislative branch that creates laws, controls federal spending, and provides oversight of the executive and judicial branches. Understanding Congress's constitutional powers helps explain how American democracy prevents any one branch from becoming too powerful.
The Three Branches of Government
The U.S. Constitution divides federal government power among three co-equal branches:
Legislative Branch (Congress)
Makes federal laws, controls the budget, and oversees the other branches. Consists of the House of Representatives (435 members) and the Senate (100 members).
Executive Branch (President)
Enforces laws, conducts foreign policy, and commands the military. Includes the president, vice president, and federal agencies.
Judicial Branch (Supreme Court)
Interprets laws and determines if they comply with the Constitution. Includes the Supreme Court and lower federal courts.
This separation of powers, designed by the Founding Fathers, ensures that no single branch can act unilaterally on major decisions. Each branch has specific powers to "check" the actions of the others, creating a balance that protects individual liberty and democratic governance.
Congress's Primary Role: Making Laws
As the legislative branch, Congress's fundamental responsibility is to create federal laws. All federal laws must begin in Congress - the president cannot create laws, only propose them and sign or veto bills passed by Congress.
The legislative process requires both the House and Senate to pass identical versions of a bill before it goes to the president for signature. Learn more about how a bill becomes a law.
Congress writes laws on everything from healthcare and education to defense and taxation. Major areas of legislative authority include:
- Taxation and government spending (appropriations)
- Interstate and foreign commerce regulation
- Immigration and naturalization
- Intellectual property (patents, copyrights)
- Declaration of war and military funding
- Federal agencies and programs
How Congress Checks the Executive Branch
Congress has several constitutional powers to limit and oversee the president and executive agencies:
1. Power of the Purse
Only Congress can authorize government spending. The president proposes a budget, but Congress controls the federal purse strings through the appropriations process.
This gives Congress enormous leverage - no federal agency or program can spend money without congressional approval. Congress can defund agencies, cut programs, or withhold funding to enforce policy priorities.
2. Impeachment and Removal
Congress can remove the president, vice president, or federal officials for "treason, bribery, or other high crimes and misdemeanors."
- House of Representatives: Votes to impeach (bring formal charges) by simple majority
- Senate: Conducts trial and votes to convict and remove from office (requires 2/3 majority)
Three presidents have been impeached (Andrew Johnson, Bill Clinton, Donald Trump twice), but none have been removed by Senate conviction.
3. Senate Confirmation of Appointments
The president nominates cabinet secretaries, ambassadors, and federal judges, but the Senate must confirm them by majority vote (51 votes).
The Senate can reject nominees, delay confirmations, or demand concessions from the president as the price of approval. This prevents the president from unilaterally installing loyalists in key positions.
4. Treaty Ratification
The president negotiates international treaties, but they only become binding if the Senate approves them by a 2/3 vote (67 senators). This ensures major foreign policy commitments have broad support and prevents the president from making international agreements that contradict Congress's legislative priorities.
5. Oversight and Investigations
Congressional committees hold hearings, subpoena witnesses and documents, and investigate executive branch actions.
Examples include investigations into executive misconduct, agency performance, military operations, intelligence activities, and regulatory decisions. While oversight doesn't directly stop executive actions, it creates public accountability and can lead to legislation or funding cuts.
6. War Powers
Only Congress can declare war. While the president is commander-in-chief of the military, Congress controls military funding and has the sole authority to formally declare war.
In practice, presidents have often ordered military action without formal declarations (most recently Afghanistan, Iraq, Syria), but Congress retains the power to defund operations or pass legislation restricting military engagement.
7. Override Presidential Vetoes
If the president vetoes a bill, Congress can override the veto with a 2/3 vote in both the House and Senate, passing the law without presidential approval. Overrides are rare but demonstrate that Congress, not the president, has final legislative authority.
How Congress Checks the Judicial Branch
Congress also has powers to check federal courts, including the Supreme Court:
1. Senate Confirmation of Federal Judges
The president nominates Supreme Court justices and federal judges, but the Senate must confirm them by majority vote. The Senate can reject nominees who are too ideologically extreme or unqualified, shaping the judiciary's composition.
2. Impeachment of Judges
Federal judges serve "during good behavior" (lifetime appointments), but Congress can impeach and remove judges for misconduct. While rare, 15 federal judges have been impeached throughout U.S. history, and 8 were convicted and removed from office.
3. Constitutional Amendments
If Congress disagrees with a Supreme Court interpretation of the Constitution, it can propose a constitutional amendment (requires 2/3 vote in both chambers, then ratification by 3/4 of states). This has been done to reverse Supreme Court decisions, such as the 16th Amendment (federal income tax) after the Court ruled it unconstitutional.
4. Court Structure and Funding
Congress determines the size of the Supreme Court (currently 9 justices, but not constitutionally required), creates lower federal courts, and controls judiciary funding. Congress could theoretically expand or contract the Court, though this is politically controversial.
How Other Branches Check Congress
The system of checks and balances works in multiple directions. The executive and judicial branches also have powers to limit Congress:
Presidential Veto (Executive Check)
The president can veto any bill passed by Congress, sending it back unsigned. Congress needs a 2/3 vote in both chambers to override, which is difficult to achieve. This gives the president significant influence over legislation.
Judicial Review (Judicial Check)
Federal courts can declare laws passed by Congress unconstitutional, effectively nullifying them. This power, established in Marbury v. Madison (1803), ensures Congress cannot pass laws that violate the Constitution.
Real-World Examples of Checks and Balances
Example 1: Impeachment of President Trump (2019, 2021)
The House impeached President Trump twice (Ukraine affair in 2019, Capitol riot in 2021), demonstrating Congress's power to hold the executive accountable. The Senate acquitted him both times, showing that removal requires bipartisan support (2/3 Senate vote).
Example 2: Senate Rejection of Supreme Court Nominee (2016)
When President Obama nominated Merrick Garland to the Supreme Court in 2016, the Republican-controlled Senate refused to hold confirmation hearings, preventing the nomination. This illustrates the Senate's gatekeeping role in judicial appointments.
Example 3: War Powers Resolution (1973)
After the Vietnam War, Congress passed the War Powers Resolution over President Nixon's veto, requiring the president to notify Congress within 48 hours of military action and limiting deployments to 60 days without congressional authorization. This reasserted Congress's war powers check on the executive.
Example 4: Affordable Care Act Ruling (2012)
The Supreme Court upheld most of the Affordable Care Act (Obamacare) but struck down the mandatory Medicaid expansion provision as unconstitutional, showing how judicial review limits congressional power even on major legislation.
Why Checks and Balances Matter
The system of checks and balances was designed to prevent tyranny and protect individual rights by:
- Distributing power: No single branch can act unilaterally on major decisions
- Requiring consensus: Major actions (war, treaties, spending) need agreement across branches
- Creating accountability: Each branch can investigate and limit the others
- Slowing change: Deliberation and negotiation prevent hasty, poorly considered policies
- Protecting minorities: Supermajority requirements (2/3 votes) prevent simple majorities from overriding fundamental rights
While checks and balances can create gridlock and slow down government action, the Founders believed this inefficiency was a reasonable price for preventing concentrated power and protecting liberty.
Learn More
Explore related topics:
- How Congress Works - Overview of the legislative process
- How a Bill Becomes a Law - Step-by-step legislative process
- House vs. Senate - Differences between the two chambers
- Interactive Map - Find your representatives and track their terms
Frequently Asked Questions
What is the role of Congress in checks and balances?
Congress checks the executive branch through the power of the purse (budget control), impeachment, treaty ratification, appointment confirmations, and oversight. It checks the judicial branch through Senate confirmation of judges, impeachment, constitutional amendments, and control of court structure and funding.
Can Congress remove the president?
Yes. The House can impeach the president by simple majority vote (bringing formal charges), and the Senate can convict and remove the president with a 2/3 vote (67 senators). Three presidents have been impeached (Andrew Johnson, Bill Clinton, Donald Trump twice), but none have been removed by Senate conviction.
What is the power of the purse?
The power of the purse is Congress's exclusive constitutional authority to authorize all federal government spending. The president proposes a budget, but only Congress can appropriate funds. This gives Congress enormous leverage over the executive branch, as no agency or program can spend money without congressional approval.
How does Congress check the Supreme Court?
Congress checks the Supreme Court through Senate confirmation of justices, impeachment and removal of judges, proposing constitutional amendments to reverse Court decisions, and controlling the size and funding of the federal judiciary. Congress determines how many justices sit on the Supreme Court (currently 9).
What checks does the president have on Congress?
The president can veto bills passed by Congress, requiring a 2/3 vote in both chambers to override. The president also influences legislation through policy proposals, the State of the Union address, and negotiations with congressional leaders. Additionally, the president can refuse to enforce laws deemed unconstitutional (though this is controversial).