Bill Radke: BP Chief Executive Tony Hayward faces a congressional hearing today. He will tell Congress and the TV cameras what led to the Gulf oil spill, how his company is cleaning it up, and of course how deeply regretful he is about the whole affair. But all these things have already been expressed, many times. So why does today’s public appearance actually matter? Marketplace’s Nancy Marshall Genzer takes a look.

Nancy Marshall Genzer: Earlier in the week, lawmakers at another hearing wanted to know why oil companies mentioned walruses in disaster management plans for the Gulf. They haven’t lived there for 3 million years. Exxon Mobil’s Rex Tillerson dutifully admitted the mistake:

Rex Tillerson: And it’s unfortunate that walruses were included.

Grill baby, grill! Politicians love skewering CEOs — it looks good to the voters back home. But does it actually lead to meaningful business regulations? Allan Lichtman is an expert on politics and elections at American University:

Allan Lichtman: These hearings can build momentum and publicity for real legislation, whatever that may be.

The hearings can also build momentum for the courtroom.

Carl Tobias teaches law at the University of Richmond. He says lawyers will be waiting for BP CEO Tony Hayward to make an incriminating statement today.

Carl Tobias: Well it’s possible that it could be used in some future case that the Justice Department might put together.

A case against BP, or Hayward himself.

In Washington, I’m Nancy Marshall Genzer for Marketplace.