Why Not a Simple Majority?
In a democracy, 50-percent-plus-one usually wins. But the architects of the Constitution were wary of what they called 'the tyranny of the majority'. They feared a slim, passionate faction could seize power and make rash, irreversible decisions. Alexander Hamilton and James Madison argued that while simple majority was fine for day-to-day legislation, certain actions were so significant they required a broader consensus. The two-thirds requirement was their solution—a constitutional speed bump designed to force deliberation, compromise, and widespread agreement on matters of the highest importance. It acts as a shield for the minority and a check on the power of the moment.
Overriding a Presidential Veto
Perhaps the most famous supermajority is the one needed to override a presidential
veto. If the President rejects a bill passed by Congress, it's not necessarily dead. Under Article I, Section 7, the bill returns to Congress, where it can still become law if both the House and the Senate pass it again, this time by a two-thirds vote in each chamber. This creates a high bar, ensuring that only legislation with overwhelming bipartisan support can overcome executive opposition. It's a powerful check that balances the power between the legislative and executive branches, though it's rarely successful; only a small fraction of presidential vetoes have ever been overridden.
Proposing a Constitutional Amendment
The Constitution was meant to be a lasting document, not one easily changed by fleeting political winds. Article V establishes a two-step process for amendments, beginning with a difficult first step: a two-thirds vote in both the House and the Senate to propose an amendment. Alternatively, two-thirds of state legislatures (currently 34 states) can call for a convention to propose amendments, a method that has never been used. This high threshold ensures that the foundational law of the country is only altered when there is a deep and broad national consensus that a change is necessary.
Convicting an Impeached Official
The House of Representatives can impeach a president, vice president, or other civil officer with a simple majority vote. But impeachment is only the charge, not the verdict. The trial happens in the Senate. According to Article I, Section 3, a conviction and subsequent removal from office requires a two-thirds vote of the senators present. This formidable requirement was designed to prevent the nation's leader from being removed by a purely partisan vote, ensuring that such a drastic measure is only taken with substantial agreement from both sides of the aisle.
Ratifying a Treaty
When the United States enters into a formal treaty with other nations, it's a serious commitment that can have long-lasting consequences. To that end, Article II, Section 2 gives the President the power to make treaties, but only with the 'Advice and Consent of the Senate', provided two-thirds of the senators present concur. This gives the Senate a crucial role in foreign policy and prevents a president from unilaterally binding the country to international agreements that lack broad support. The high bar often leads presidents to use 'executive agreements', which don't require Senate approval, for less monumental accords.
Expelling a Member of Congress
Each house of Congress has the power to police its own members. Under Article I, Section 5, both the House and the Senate can expel one of their own for 'disorderly Behaviour'. But to prevent a majority party from simply kicking out political opponents, the Constitution requires a two-thirds vote for expulsion. This is the most severe form of punishment Congress can inflict on a member, and its high threshold ensures it is reserved for only the most serious cases of misconduct. James Madison himself argued that the power of expulsion was too important to be left to a simple majority.
Other Notable Two-Thirds Votes
A few other scenarios also trigger the two-thirds rule. The 14th Amendment, for instance, bars anyone who has engaged in 'insurrection or rebellion' from holding office, but allows Congress to remove that disability with a two-thirds vote of each House. And the 25th Amendment provides a process for the Vice President and Cabinet to declare a president unable to serve; if the president contests this, a two-thirds vote in both chambers is required to keep the vice president in charge as Acting President. Finally, if no candidate wins the vice presidency in the Electoral College, the Senate decides, with a quorum requiring two-thirds of all senators.
