For America, measuring the extent of Barack Obama's anger at BP over the Gulf crisis has become almost as important as measuring the extent of the spill itself. But on one thing everyone is agreed: while the latter is far too high, the former remains too low.
Try as he may to ratchet up the public show of fury, a President celebrated for his cool demeanour never seems to do enough. As the weeks since the 20 April disaster passed, the questions multiplied. Did he truly understand how much damage was being done? Did he really care? A majority of Americans, polls show, are unhappy at his handling of the crisis.
Yesterday, Mr Obama used his heaviest rhetorical artillery yet. If the decision were his, he told NBC's Today programme, he would have long since fired Tony Hayward, BP's chief executive.
And, he argued, his determination to learn the facts was no sign of lack of concern. Indeed it was precisely the opposite. "I don't sit around just talking to experts because this is a college seminar; we talk to these folks because they potentially have the best answers, so I know whose ass to kick."
The assumption that the ass in question belonged to BP sent the company's stock tumbling another 5 per cent yesterday. Whether such bar-room language persuades Americans his outrage has finally reached the appropriate level is another matter.
From the start, Mr Obama has struggled to match his perceived emotions to those of the country. "Just plug the damn hole," he is said to have fumed to aides, a month into the spill. But that did not suffice. So last week he upped the public exasperation."I am furious at the entire situation," he told the CNN host Larry King in an interview. But "if jumping up and down and screaming could fix a hole in the ocean, we'd have done that five or six weeks ago".
But exactly what form did the presidential anger take, reporters wanted to know. How, for instance, did Robert Gibbs know that his boss was, as the White House spokesman claimed, "enraged" by the disaster? The reply alas was less than convincing. Mr Obama had been "in meetings – clenched jaw – even in the midst of these briefings, saying everything has to be done".
The problem of course is that histrionics is not the Obama way. Bill Clinton was the acknowledged master of empathy; indeed, the single thing that put his presidency back on course after the November 1994 mid-term defeat was his response to the Oklahoma City bombing five months later. Mr Clinton's words of grief and compassion, anger and resolve, articulated exactly how his compatriots felt.
But the Oklahoma blast, at the time the worst terrorist outrage in US history, was simple in comparison with the crisis in the Gulf. The bombing happened, and was over. The oil spill is a real-time continuing disaster, which the government is powerless to block.
Implicitly, it saps at his authority every day, violating the assumption that the man in the Oval Office is omnipotent. Whatever his loathing of BP, this President knows he is dependent on the company – and a foreign company at that – to solve the crisis. The country is fearful, indignant and frustrated at its impotence, in a mood to lash out at those responsible, even though mere lashing out will change nothing. The reports of BP's alleged negligence, its readiness to sidestep safety rules, only add to the rage. Some of that rage will be vented next week when Mr Hayward is hauled before a House committee in public session to answer for his sins.
For Mr Obama, however, it is harder. He tries to articulate the national exasperation. But fierce emotional words, and the instant gratification they bring, are not his preferred way – and however hard he tries, it shows. The Obama method is a withering fury, steeped in sarcasm.
"Obviously," he told NBC, "You cannot take the word of oil companies when they say they've got a bunch of back-up plans when something like this happens, and it turns out they have no idea what they're doing."
Yesterday brought more revelations, in a report by The Washington Post and the organisation ProPublica, that the company had "systematically ignored its own safety policies across its North American operations," and even promoted some executives responsible for the mistakes.
Civil fines could amount to $3,000 per barrel split. At a rate of 20,000 barrels a day (though no one knows the precise figure) over 50 days, that adds up to a fine of $3bn and counting, on top of private and public lawsuits and punitive damages.
But for Mr Obama the dilemma remains. The "No Drama, Obama" style that worked so well on the campaign trail is no match for this crisis. Presidents are expected to work miracles. No miracle can right the damage already done.