Democrats are threatening to expand the Supreme Court if President Trump’s nominee is confirmed, but whether the threats have any legs comes down to the position of Washington institutionalist Joe Biden.

Senate Majority Leader Mitch McConnell’s intention to proceed with filling the late Justice Ruth Bader Ginsburg’s seat, despite early voting for the Nov. 3 election being underway, has prompted calls from those in the left wing for a no-holds-barred retaliation in the event that he succeeds in confirming a Trump nominee. Assuming Democrats win control of both the Senate and the White House, they want to increase the number of justices on the Supreme Court up from nine and fill the new seats with Democrats’ choice of liberal-leaning justices — swaying the jurisprudence of the court for years.