The Constitution specifies a three-fourths majority for just one process. What?
http://www.law.cornell.edu/constitution/constitution.table.html#articlei
Scroll down and read Article V.
=)
http://caselaw.lp.findlaw.com/data/constitution/amendments.html
The Constitution specifies a three-fourths majority for the process of proposing and ratifying amendments.
To understand how this is specified, we can refer to the United States Constitution, specifically Article V.
1. The process of proposing an amendment requires a three-fourths majority of both houses of Congress. This means that in order to propose an amendment, it must be approved by a supermajority, or three-fourths of the members of the House of Representatives and the Senate.
2. Once an amendment is proposed, it then needs to be ratified. The Constitution provides two methods for ratification:
a) Ratification by the state legislatures: After an amendment is proposed, it must then be ratified by three-fourths (i.e., 38) of the state legislatures. This is achieved when three-fourths of the states, usually through their respective legislatures, approve the amendment.
b) Ratification by state conventions: Alternatively, an amendment can be ratified by three-fourths of state conventions, which are specially elected bodies created for the purpose of deciding on the ratification of the proposed amendment.
In both cases, a three-fourths majority is required for the amendment to be ratified and become part of the Constitution. This high threshold reflects the framers' intent to ensure that any changes to the Constitution have significant support and are not easily achieved.