What part of the federal government can prevent the president of the united states from controlling the supreme court by blocking appointments to the bench?

Senate

Explanation:

Senate of the Federal government can prevent the President of the United States from controlling the Supreme Court by blocking appointments to the bench.

It keeps a check on the government by scrutinizing bills, delegation of legislation, administrating the government and taking care of the policies of the government in general. It works through the Senate chamber and operates through the Senate committee system.