A more thorough explanation:

A court-packing plan is a proposal to increase the number of justices in a court system. The most famous example of this is President Franklin D. Roosevelt's proposal in 1937 to increase the number of justices on the U.S. Supreme Court from 9 to 15.

The purpose of the proposal was to appoint justices who would not block his administration's New Deal programs. Roosevelt claimed that the increase in justices would make the Court more efficient, but many saw it as an attempt to manipulate the Court for political gain.

President Roosevelt's court-packing plan was met with widespread opposition, including from members of his own party. The plan was eventually defeated in Congress, but it sparked a national debate about the role of the Supreme Court in American politics.

Another example of a court-packing plan is currently being proposed in some states, where politicians are attempting to increase the number of judges on state courts in order to appoint judges who align with their political views.

These examples illustrate how court-packing plans can be used as a political tool to manipulate the judiciary for partisan gain. They also show how controversial and divisive these proposals can be, as they often raise questions about the independence and integrity of the court system.