LAST MONTH Senate Republicans unjustifiably blocked an up-or-down confirmation vote on Caitlin J. Halligan, nominated by President Obama to fill one of four empty spots on one of the country’s top courts, the U.S. Court of Appeals for the District of Columbia Circuit. Despite her impeccable credentials and the support of conservative legal luminaries, only a single Republican voted to break a GOP filibuster.

How far will this unwarranted obstruction extend?

Wednesday, Post blogger Jonathan Bernstein notes, the country might very well find out. The Senate Judiciary Committee will hold hearings on the president’s other nominee for the D.C. Circuit, Principal Deputy Solicitor General Sri Srinivasan, whose gold-plated legal resume is outmatched only by the glowing terms conservative advocates such as Theodore B. Olson, Kenneth W. Starr and Paul Clement used in their endorsements of his nomination. Mr. Srinivasan clerked for the Reagan-appointed Justice Sandra Day O’Connor; he served with distinction in both the President George W. Bush and Obama Justice Departments. In his current job, his name has been inscribed on some top-rate briefs the government submitted to the Supreme Court.

In advance of the confirmation hearing, the Obama administration has been making public and private appeals on Mr. Srinivasan’s behalf. Much has been made of the political stakes. Judges on the D.C. Circuit regularly ascend to the Supreme Court. Unlike his predecessors, Mr. Obama did not get any of his nominees onto the powerful appeals court in his first term. During that time, the D.C. Circuit’s one-vote conservative majority repudiated some of the president’s policies.

But it would be a counterproductive mistake for lawmakers to confuse consideration of Mr. Srinivasan’s nomination with a vote on the Obama years or policies. It’s not. It’s about the institutional interest that both parties have in allowing presidents to staff the government and judiciary with well-qualified nominees of their choice, a norm that senators of both parties have eroded, we hope not irreparably.

“That the Senate has since 1993 denied confirmation to three of every ten circuit nominees reflects a new (and unfortunate) normal,” Brookings Institution’s Russell Wheeler wrote in a recent analysis. The filibustering of D.C. Circuit nominees in particular did not begin with Ms. Halligan. During Mr. Bush’s first term, Democrats denied the well-qualified Miguel A. Estrada a spot on the court, to which Republicans reacted with understandable outrage.

It’s Republicans who are doing the obstructing now, and, no matter who started it, it has to stop. If it does not, a frustrated majority party will at some point give in to temptation and strip the minority of its senatorial prerogatives — a result that both parties will rue in time.