A single Senate vacancy could plunge the future of the Biden-era high court into uncertainty, given Democrats’ tenuous 50-50 majority. Yet despite that risk, and the obvious consequences of Ginsburg’s decision to stay on after 2014, Supreme Court retirements remain a third rail in Democratic politics — at least publicly. Many of the party’s senators declined to predict whether or not a justice would step aside this year, although they’re acutely aware of the stakes of Breyer’s decision-making after watching Senate Republicans fill three Supreme Court seats in just four years. "It's self-evident that if you care at all about the balance of power on the Supreme Court then you have to not hang on until the very last moment," one Democratic senator said of Breyer. "He should enjoy his retirement and allow us to put in a talented younger jurist that can serve for decades."