“The Constitution provides that there must be a Supreme Court, but it does not set the number of justices — that number is set by Congress. The Judiciary Act of 1789 originally established a six-justice Court, and this number vacillated considerably during the nation’s first century. The number of justices briefly grew to 10 during the Lincoln administration, before finally settling at nine under President Ulysses S. Grant.
If Democrats control the White House and the Congress, in other words, they can pass a law adding seats to the Supreme Court. If Biden is president, he could then quickly fill them (with the consent of the Senate). And four new seats could give Court a Democratic-controlled majority, despite another Trump pick.
It’s a risky play. At the height of his popularity, President Franklin Roosevelt proposed expanding the size of the Supreme Court to 15 in order to neutralize five reactionary justices who frequently undercut the New Deal. It did not end well for him. Many historians cite the court-packing plan as the event that shattered Roosevelt’s political coalition and left him unable to pass liberal bills through Congress.
But these are very different times. In 1937, when Roosevelt proposed packing the Court, every one of the Court’s nine justices could claim that they got there fair and square. No one was on the Supreme Court because one political party invented a fake rule, applied it harshly to a president they loathed, and then immediately scrapped that rule when it was inconvenient.
Trump’s two previous Supreme Court appointees, Justices Neil Gorsuch and Brett Kavanaugh, also share a dubious distinction. They are the only members of the Supreme Court in history to be nominated by a president who lost the popular vote and confirmed by a bloc of senators who represent less than half of the country. If Trump fills the Ginsburg seat, fully one-third of the Court will be controlled by judges with no democratic legitimacy.”