This article is part of David Leonhardt’s newsletter. You can sign up here to receive it each weekday.

Congressional Democrats haven’t done an especially good job of investigating President Trump’s misdeeds over the past few months. They have held no hearings of significance since Michael Cohen, Trump’s former lawyer, appeared in February, and they’ve had a confusing public message that probably hasn’t persuaded anyone who didn’t already think that Trump was unfit for office.

Today, the Democrats get a new chance to clarify their message, when Robert Mueller appears before the House. Here’s what members of Congress should try to accomplish during the hearing:

Keep it simple. “The televised hearing will be the first chance most Americans have to hear what’s really in the report, right from the man who wrote it,” Garrett Graff, the author of a book about Mueller’s leadership of the F.B.I., writes in Wired.

For that reason — and because Mueller has said he would not talk about issues beyond his report — members of Congress should use the hearing as a tutorial for the American people on all of the alarming information in the report. “Even if Mr. Mueller refuses to say anything beyond the contents of his report — as is expected — his televised testimony can serve as a valuable explainer and a much-needed corrective,” The Times’s editorial board points out