Lois Lerner is lucky that she’s testifying at a congressional hearing rather than at a criminal trial. In a courtroom, if Lerner were a defendant, then she couldn’t have simply read an “opening statement” and then refused to testify further; her statement would’ve “opened the door” to questioning about the subjects she raised (and then there are further wrinkles in civil, as opposed to criminal, cases). Before the House Oversight Committee, however, Lerner is merely a witness at an investigative hearing—and one compelled to attend by subpoena, no less—so she can “selectively” invoke her Fifth Amendment right not to answer particular questions that may incriminate her or to cut off questioning altogether.

Still, Lerner said four things that should pique Congress’s interest: (1) “I have not done anything wrong.”; (2) “I have not broken any laws.”; (3) “I have not violated any IRS rules or regulations.”; and (4) “I have not provided false information to this or any other committee.” The committee should do all it can to investigate Lerner’s understanding of the laws and regulations she was applying, and how her previous oral and written testimony comport with the IRS malfeasance under review.

It certainly looks fishy that Lerner has decided not to answer questions on these issues, but Rep. Darrell Issa (R‑CA) can’t force her to do so.

What he can do is call Lerner back and have her prior testimony read, asking how her current knowledge of what went on compares to her earlier statements — and any other questions the committee has. This would force her to “plead the Fifth” on every question, which would put pressure on the IRS and its political masters, even if Lerner doesn’t have to answer. He could also, now if there’s enough evidence of wrongdoing already or later if there will be by the end of the investigation, move for a criminal indictment.