5
5 votes create a majority in the Supreme Court.
Supreme Court
The Supreme Court is the highest court in the United States. This means that the decisions of the Supreme Court supersede all other courts. When the lower courts' decisions are appealed, the Supreme Court helps settle disputes between people and groups. Additionally, the Supreme Court has the duty of ensuring that all laws are constitutional. The Supreme Court has the ability to repel laws that it deems unconstitutional.
Majority
There are 9 Justices serving on the Supreme Court. To have a majority, you need over half all the possible votes. This means that it requires 5 votes to create a majority. However, it is possible for justices to abstain and create a majority with only 4 votes. Nevertheless, 5 votes are the only way to ensure a majority.