The fight over Supreme Court nominee Neil Gorsuch isn’t just over whether senators will vote for him. It’s also about how many votes he needs, exactly. Led by Minority Leader Chuck Schumer, some Democrats argue that Gorsuch needs to get 60 votes to overcome a filibuster and be confirmed, which they claim is a historical standard. “To my Republican friends who think that if Judge Gorsuch fails to reach 60 votes we ought to change the rules I say: if this nominee cannot earn 60 votes, a bar met by each of President Obama’s nominees, and President Bush’s last two nominees, the answer isn’t to change the rules — it’s to change the nominee,” Schumer said last week. But Republicans counter that the filibuster was rarely used in the past and point out that two justices currently sitting on the court were confirmed with fewer than 60 votes—Justice Clarence Thomas by 52 votes in 1991 and Justice Samuel Alito by 58 votes in 2006. “The fact is, an attempted filibuster of a Supreme Court nominee is rare, and to do so in this context, with such an eminently qualified and brilliant judge is nothing short of obstructionism,” White House spokesman Sean Spicer said Monday, adding that it “undermines decades of Senate tradition.” Constitutional experts say both sides have a claim, though the Republican argument is the stronger one.