Former Trump lawyer and fixer Michael Cohen is scheduled to appear before three congressional committees this week before he heads to jail to serve a sentence for tax evasion and lying to Congress. On Tuesday, Cohen will testify before the Senate Intelligence Committee. On Wednesday, he will go before the House Oversight Committee. And on Thursday, he will testify before the House Intelligence Committee.

It would be a great service if the Cohen appearances helped increase the store of public information on the Trump-Russia furor. But even though Cohen is a key figure in the matter — his name is mentioned 24 times in the so-called Trump dossier — the hearings appear designed to prevent the public from learning anything new about the Russia matter.