Americans depend on the Supreme Court to address the most important and most complicated questions about our laws, and the justices have plenty of those on their calendar this term, with cases ranging from voting rights to abortion to campaign finance.

But since Justice Antonin Scalia’s unexpected death in February, the court has been hearing cases with only eight justices, opening the door to 4-4 tie votes that will leave questions unanswered and litigants in limbo. Although veteran federal Circuit Judge Merrick Garland was nominated by President Obama in March, the court’s open seat remains unfilled because the Senate majority refuses to hold a hearing or vote until after the presidential election.

When the court divides 4-4, the rulings made by the lower courts are upheld, and no national precedent is set. That’s “essentially the same as a denial of review,” Justice Ruth Bader Ginsburg argued recently. And when lower courts disagree on the issues, as the “(more liberal) U.S. Court of Appeals for the 9th Circuit and the (more conservative) 5th Circuit”  often do, the result is a hodgepodge of laws and enforcement across the country.

Ginsburg, who argues that eight justices “is not a good number for a multi-member court,” is not the first to make that case. In 2004, Scalia, who in many ways was Ginsburg’s ideological opposite on the court, also stressed the importance of having nine Justices.

How often does a decision come down to the final vote? A recent report by the Constitutional Accountability Center and People for the American Way discovered that the court has had a higher frequency of 5-4 split decisions in the last 10 years than ever before. During this term, the court decided 22% of its cases by a single vote.

Eric Segal, a professor at Georgia State University College of Law, argues that 4-4 splits may actually be good for the court. The ninth “swing vote” has often been Justice Anthony Kennedy’s, giving Kennedy disproportionate power over the court. Segal noted that Kennedy has been the deciding vote in 85% of 5-4 cases in the past 10 years. As a result, Segal contends that an even-numbered court will lead to more compromise and moderate rulings instead of decisions that hinge on a single vote.

Other scholars suggest that when it comes to the Supreme Court, compromise isn’t always the best outcome. Elizabeth Wydra, president of the Constitutional Accountability Center, asserted recently that “we expect our court to be able to provide answers to questions of exceptional national importance that come before it — and sometimes the law and the Constitution demand an answer, not a compromise.”

Issues surrounding the court’s lack of a ninth justice are a direct result of the Senate’s refusal to vote on the Garland nomination. The President forwarded his name 85 days ago, the same number of days senators needed to confirm Justice Scalia in 1986. Today, as we observe that milestone, we must continue to demand that our Senate does its job.