Senate Majority Leader Mitch McConnell of Kentucky said at a Tuesday news conference that all Republicans on the Senate Judiciary Committee oppose holding a hearing on any nominee submitted by President Obama to replace the late Supreme Court Justice Antonin Scalia. (The Minnesota Star Tribune)

In October 2013, while Republicans in Congress shut down the government for 16 days, the Supreme Court began its term as usual, and, unlike most other federal government institutions, the Supreme Court building remained open to the public.

The wheels of justice turn slowly, but the GOP now threatens to bring them to a halt. Republicans' latest plan is to shut down the Supreme Court. Call it Government Shutdown 2.0.

The Republican leadership has pledged that the Senate will not confirm anyone President Obama selects to fill the late Justice Antonin Scalia's seat, regardless of the candidate's qualifications. The next president, they argue, should make the appointment.

This unprecedented obstructionism would, in effect, block the Supreme Court from conducting some of its core functions for more than two years. Over the past decade, up to a third of the court's docket has been decided by 5-4 votes. Without a full bench, the court may be unable fulfill its main role: to resolve conflicts in the interpretation of federal law and the Constitution.

If some appellate courts interpret a law in one way but other appellate courts disagree, the result is a dysfunctional law. For example, the Eighth Circuit Court of Appeals, which includes Minnesota, ruled that the Affordable Care Act's contraception exemption procedures for religious employers violate federal law, while all other appellate courts to consider the question upheld those provisions. The Supreme Court will hear argument in these cases next month, and would ordinarily issue a decision by the end of June, resolving the conflict and restoring uniformity and predictability to how courts apply federal law.

But not if Republicans have their way. If Scalia's seat remains vacant, there is a risk that particularly contentious cases, like challenges to the Affordable Care Act, will result in a 4-4 split at the high court. What happens then? The most likely result is the court will affirm the lower court's decision, with no opinion and no precedent to guide lower courts in resolving the conflict.

What does that mean? For the contraception exemption, for example, it would mean that religious employers in Stillwater wouldn't have to fill out the exemption form, while religious employers just across the river in Hudson, Wis., would. The court would have to wait for a new case — and a new justice — before it could take another stab at resolving this inconsistency.

The court has another option: It could hold the 4-4 cases and schedule reargument after a new justice is seated. But when would that happen? The confirmation process typically takes at least two months, so even if the new president names a nominee on Inauguration Day, the new justice probably wouldn't be sworn in before April 2017. But the court has its last oral arguments for the term in April, and those arguments are scheduled many months in advance. The soonest the court could schedule cases for reargument before a full panel of nine justices would be October 2017, when the next term begins.

The court begins to issue decisions from the October arguments in late November or early December, but more controversial cases — cases more likely to result in 5-4 decisions — often take months longer. Opinions in some of those cases might not be handed down until the end of the term: June 2018.

These protracted delays would have a ripple effect. Some controversial cases carry other lower court decisions in their wake. If the court agrees to hear a case and other cases arise concerning the same legal issue, the court typically "holds" those related cases until the main case is resolved, and then, as appropriate, remands the other cases to the lower courts for reconsideration in light of the court's new opinion. Over the course of a single term, one case may keep over a dozen other cases in limbo. Over two or even three terms, that limbo list would multiply.

To ensure a fully functional third branch of government, Senate Republicans should promptly hold hearings on Obama's nominee and bring the nomination to a vote. As retired Justice Sandra Day O'Connor put it: "We need somebody in there to do the job and just get on with it."

Amy Bergquist, of Minneapolis, is an attorney who clerked for U.S. Supreme Court Justice Ruth Bader Ginsburg in 2010-11.