Are we the only paper that is not entirely comfortable with the arrest of the speaker of the New York Assembly, Sheldon Silver, on charges handed up by the federal government? On what authority is America reaching into the legislature of New York State? In the most famous case of the federal government doing that in recent years, its target — Senator Joseph Bruno, the majority leader — was forced out of the state legislature. Yet the honest services statute that the Feds used against him was ruled unconstitutional by the United States Supreme Court, and when senator was re-tried, he was discovered by the court to be not guilty.

It’s not our purpose here to mount a defense of Mr. Silver. We have occasionally observed that the so-called “reform” candidates that have been put up against him in the primaries were hard-left figures, in comparison to whom Mr. Silver looked like Athena herself. But he is, among other things, a Democrat, and, in any event, his compensation for secret legal work would be appalling, even if it turns out to be legal. His big wrong is his failure to allow democratic debate in the Assembly. It was exemplified, these columns have noted, by his refusal to grant religious New Yorkers, Orthodox Jews and Catholics, any hearing on same-sex marriage, a refusal that tarnished the legislature’s standing on the question.

Mark, in any event, that the charges being levied against Mr. Silver are being brought under the law of honest services. This is dangerous ground. The use of the honest services statute was drastically curtailed by the Supreme Court in the separate cases brought by Jeffrey Skilling of Enron and Conrad Black. The ruling — that the law was unconstitutionally vague — was not five to four, or six to three, or seven to two, or even eight to one. It was nine to zero, as in unanimous. There were no dissents. The solons all agreed: Ruth Bader Ginsburg and Clarence Thomas and everyone in between. It’s a dangerous law.

The Supreme Court didn’t strike down the whole honest services theory. But it did curtail its use, limiting it to bribery and kickbacks. That’s of what Senator Bruno was accused — and Silver, too. The thing about these kinds of laws is that they tempt prosecutors onto ice that turns out to be thin. Mr. Bruno was acquitted, long after his career was wrecked. What would have happened had he not resigned and tried to out tough it? Could he have remained the leader of the Senate? History doesn’t disclose her alternatives. Everyone is urging Mr. Silver to resign. He says he hopes to be vindicated in court. On what consistent standard is one supposed to proceed in these cases?

We would have felt better about this had it been handled by New York State. There the blame belongs to Attorney General Eric Schneiderman, who has emerged as a weak player, and Governor Andrew Cuomo, who disbanded the Moreland Act Commission he himself had set up. His default appears to have been animated by a fear that it would reach deep into the Democratic power structure in Albany, a fear that seems well-placed given the charges that have just been handed up against the only Democrat more powerful than Mr. Cuomo. The governor himself has reportedly lawyered up. The failure of the state to keep its own house is part of the shame of New York.