A rare campaign-finance ruling worth cheering came from the U.S. Supreme Court last week. "Judges are not politicians," Chief Justice John Roberts wrote for the 5-4 majority in a decision upholding a rule in Florida — and Minnesota — prohibiting judges and judicial candidates from personally soliciting campaign contributions.

"A state's decision to elect its judiciary does not compel it to treat judicial candidates like campaigners for political office," Roberts wrote.

A bar on judges rattling a tin cup for their own campaigns seems so basic to the ideal of an impartial judiciary that it should hardly be in question. In fact, it has not been in 30 of the 39 states that elect judges — including Minnesota, where such a bar extends to a prohibition on judges seeing the campaign-finance reports filed by their own campaigns.

But the U.S. Supreme Court's own decisions in prior cases, including one from Minnesota, likely emboldened Florida plaintiff Lanell Williams-Yulee, an unsuccessful judicial candidate, to challenge her Florida Supreme Court reprimand and fine for signing a letter soliciting campaign cash. In 2002 — also in a 5-4 ruling — the high court struck down Minnesota's bar on judicial candidates discussing legal disputes while campaigning. And the court's liberality on corporate funding of political campaigns was much in evidence in the 2010 Citizens United decision.

Against that backdrop, advocates for judicial independence from special interests were overjoyed by the high court's Williams-Yulee decision. It leaves us hoping that the court might consider anew whether the same concern ought apply to the legislative and executive branches.

Meanwhile, we hope that the Roberts decree — "judges are not politicians" — is taken to heart by political parties in this state. The Republican Party was embarrassed last year by its endorsement of an unsuitable candidate for the state Supreme Court. To their credit, some in that party have called for an end to judicial endorsements, which only the GOP has opted to bestow in the modern era. Their argument was just bolstered by the chief justice of the United States.