GRAND ISLE, La. - Dogged for being too calm in crisis, President Obama unleashed frustration for all to see yesterday, warning BP it had better do right by the people whose lives it has wrecked.

The president's third trek to the Gulf of Mexico was about the workers with no government titles, the shrimpers and the shopkeepers, the fishermen whose lives have been upended and are running out of people to blame.

Yet Obama's trip was also about him.

He says it serves little substantive point to go around and yell - that people want results, not a show - but presidents face peril if they do not connect emotionally. As the crisis has dragged on - and his poll ratings have slipped - his words for BP's leaders have grown sharper.

"I don't want them nickel-and-diming people down here," Obama said after his latest briefing on the oil response. He promised his government would look over BP's shoulder to ensure it was paying out claims.

His visit amounted to one long I'm-on-your-side passage for reeling communities. Along that same line, he invited family members of the 11 workers killed when the BP rig blew up to visit the White House next Thursday. Press Secretary Robert Gibbs said the president had written to each of the families.

As for BP, Obama cast the oil company as a corporate giant interested in protecting its image with TV ads and its shareholders with bountiful dividends.

"I don't want somebody else bearing the costs of those risks that they took," Obama said. "I want to make sure that they're paying for it."