President Joe Biden has made clear that one of his administration’s top priorities will be furthering racial justice, and a critical pillar of any plan must be remaking our federal courts. However, much as the filibuster stands in the way of progress on a host of key legislative priorities, another, lesser-known Senate tradition weaponized by segregationists and today’s Republican Party could derail any serious effort at diversifying our courts.

Remaking the federal judiciary is critical for making serious progress toward racial justice on issues ranging from police violence to voting rights. While Americans often associate the courts with landmark civil rights decisions, the reality today is that our courts and former President Donald Trump's nominees to them are an obstacle to, not an ally of, racial justice movements. Trump’s judges are also the least diverse group in decades. 

Biden has committed to appointing diverse, pro-civil rights lawyers to the bench, and he has promised to nominate the first Black woman to the Supreme Court.

Even so, a Senate procedure known as Blue Slips could grind to a halt his efforts to remake our judiciary. Senate Democrats must now make a choice: Honor an arcane Senate tradition that has stood in the way of racial justice for decades, or discard it in the interest of moving our legal system toward the promise of equal justice under the law.

While little known outside the halls of Congress, the Senate’s Blue Slip tradition is one of the most important factors in deciding who does and does not become a federal judge in America. For decades, it has been used by opponents of racial justice to keep people of color and pro-racial justice judges off the bench. Much like its better known cousin the filibuster, it is a counter-majoritarian tool that was embraced by segregationists and now threatens our ability to make progress on contemporary racial justice issues.

The Blue Slip process requires both senators from a state where a judge would sit to approvingly return a piece of paper — the titular "blue slip" — before the nomination is considered. While it might sound innocuous, it has often been used to throw sand in the gears of progress on racial justice. Blue Slips as we know them were created by segregationists to block pro-civil rights judges in the aftermath of Brown v. Board of Education. Following the Supreme Court’s school desegregation decision, Mississippi Sen. James Eastland, an avowed segregationist and chair of the Senate Judiciary Committee, created a policy that would allow white Southern senators to quietly veto pro-civil rights picks for their home states without forcing their colleagues to take a public position.

As I advised President Barack Obama on judicial nominations, I saw many Republican senators follow the Eastland approach, vetoing dozens of highly qualified nominees and potential candidates — disproportionately lawyers of color and women — through the Blue Slip process. Democrats cannot let that happen again.

From 2009-16, almost 20 of President Obama’s judicial nominees were denied a confirmation hearing because of a negative or unreturned Blue Slip from Republican senators. All were either women or people of color, and the majority were Black. Republican senators, such as Jeff Sessions and Ted Cruz, also wielded their Blue Slips to veto many suggested Obama candidates, leaving many judicial vacancies without even a nominee.