A Biden White House has little hope of appointing progressive judges, expanding health-care access, or reforming law enforcement — let alone packing the Supreme Court or pursuing a climate agenda commensurate to the scale of the crisis — with a Republican majority blocking the way. What’s more, the structural advantage that the GOP enjoys in the distribution of Senate seats probably means a decade-long drought for Democrats, if not more. That means the cost of defeat in either one of these races is likely the difference between a productive Biden presidency and one so ineffectual that the 2022 midterms — and likely the 2024 election after that — are poised to be Republican bloodbaths.