To pack the high court, Schumer would not only need a Democratic president, he would need to eliminate the Senate filibuster. Changing that rule would be a huge step — and a very controversial one — because it would permanently change the way Congress operates. Once the filibuster is gone, it will be gone forever. The Senate would then resemble the House, where the minority is powerless and the majority can ram through any bills it chooses. Such a change would significantly alter the Founders’ framework, which establishes multiple “veto points” on government action.

Without the Senate’s ability to pump the breaks with a filibuster, a Biden White House could swiftly pass major Democratic initiatives on tax rates, immigration laws, health care, the Green New Deal, and more. They could choose to add two new, presumably reliably Democratic states: the District of Columbia and Puerto Rico, hoping to lock in their party’s control of the Senate for years to come. They could choose to pack the Supreme Court with additional justices. Their argument: The Republicans had acted illegitimately by replacing Ginsburg, so they are only offsetting that maneuver and “rebalancing” the court. (Of course, there would be nothing to prevent a future Republican president and Senate from adding still more justices.) In a country that is evenly split, the minority would have no say at all unless it controlled the presidency or one house of Congress.

Democrats would have no incentive to abolish the filibuster if Trump is reelected. But they could still force a constitutional crisis if they won the Senate and resolved to block Trump’s judicial and Cabinet nominees.