The U.S. Constitution established the Supreme Court but left it to Congress to decide how many justices should make up the court. The Judiciary Act of 1789 set the number at six: a chief justice and five associate justices. In 1807, Congress increased the number of justices to seven; in 1837, the number was bumped up to nine; and in 1863, it rose to 10. In 1866, Congress passed the Judicial Circuits Act, which shrank the number of justices back down to seven and prevented President Andrew Johnson from appointing anyone new to the court. Three years later, in 1869, Congress raised the number of justices to nine, where it has stood ever since. In 1937, in an effort to create a court more friendly to his New Deal programs, President Franklin Roosevelt attempted to convince Congress to pass legislation that would allow a new justice to be added to the court--for a total of up to 15 members--for every justice over 70 who opted not to retire. Congress didn't go for FDR's plan.
Congress is in charge of this, and the Republicans are in charge of Congress.
As the Republican's in Congress have proven time and again these past seven years with Obama in the White House, they are NOT to be trusted!
And Mitch McCOnnell is in charge of the Republicans and Harry Reid and Barak Hussein are in charge of Mitch McConnell.