A seat on a top court opens. It is the chief executive’s duty to nominate someone to fill it. From there, when governments are divided on partisan lines, politics can take over.

That’s the case in Washington, D.C., where a seat is vacant on the Supreme Court after the death of Justice Antonin Scalia. President Obama sent word to Republican leaders in the Senate that he wanted to discuss how the two branches of government would work together to fill the vacancy. According to news accounts, the White House waited for a response. And waited.

Senate Majority Leader Mitch McConnell has decided that his chamber will only consider a nomination from the next president, not Obama. According to the Constitution, it’s a chief executive’s duty to choose a justice and the Senate’s to confirm that choice unless there’s a legitimate reason not to. McConnell’s intransigence shows how wrong it can go. It’s possible that if a Democrat succeeds President Obama, his or her nominee could be blocked — or Democrats in the body could filibuster a nominee by Republican victor.

But here in Massachusetts, we get a glimpse of another way.

Just a year into his term as governor, it is falling to Charlie Baker, a Republican, to significantly reshape the Supreme Judicial Court by filling three vacancies this year and two next year. That’s five of the seven seats on the state’s highest court, which has been hearing appellate cases since 1692 and is considered the oldest of its kind in the Western Hemisphere.

Court appointments have lasting policy implications for governors and presidents. In Washington, President Obama’s goal would be to seat a justice who, unlike Scalia, a strict constitutionalist and conservative, will tip the court’s ideological balance to the left.

That’s possible on the Supreme Court with just one appointment. Here in Massachusetts, Baker’s appointments will remake the entire court. That is a solemn duty that Baker appears ready to share in a relatively nonpartisan fashion.

The governor recently appointed 12 people, including Northampton attorney John P. Pucci, a former federal prosecutor, to compile a list of candidates for the high court. The panel will identify candidates with great qualifications and personal integrity, most of all, but also with geographic and racial diversity. Baker’s choices from that roster will go to the Governor’s Council for confirmation within the next six months. Three will be seated when the court’s term begins in September, following the retirements of Francis Spina, Robert Cordy and Fernande Duffly.

Pucci notes that history is being made, since this may be the first time three justices will join the court at the same time. Next year, the SJC will lose Geraldine Hines and Margot Botsford, both of whom will hit the mandatory retirement age of 70.

It’s possible that when the three new jurists begin work in Boston, the U.S. Supreme Court will be a month from starting its new term still down a justice, leaving the remaining eight to hear cases they know may reach split votes. When that happens the lower court’s ruling is affirmed and no precedent can be set.

The stakes are higher in D.C., but the system of choosing and confirming justices is basically the same.

The system is, but the political climate is not. In Washington, the only thing likely to be confirmed is the sad fact of partisan rancor within McConnell’s Senate.