Last week was, I thought, President Obama’s best week. The proverbial split-screen of television news had him traveling the Midwest, visiting factories, sleeves rolled up, talking up the beginnings of the economic recovery that is restoring consumer confidence and hopefully, soon, will bring down the unemployment rate. Back in Washington, his political opponents were cast in the role of defenders of the very same people who brought on the economic collapse, and while the GOP leaders said they favored reform, just not this reform, that mantra had become a little too familiar to be believed. When executives from Goldman-Sachs appeared before a Senate panel, looking precisely as guilty and lawyered-up as the tobacco executives did a couple of decades ago, the opposition collapsed and a bipartisan bill appears in the offing.

Then came the oil catastrophe off the coast of Louisiana to remind the President, and the rest of us, of the limits of his powers. Here was a problem that did not need a President or a politician but an engineer. Here was a problem that was immediate, with short term economic as well as long-term environmental consequences, and the normal tools of presidential authority do not serve. As King Canute learned, political authority does not extend to the waves. Yes, there will be plenty of analysis about what went wrong and how to fix it, but the bottom line for Obama is that this mess threatens the most important premise of his political platform, re-establishing the idea that the government can accomplish good things for the American people.

If the oil mess was not humbling enough, along comes Mr. Faisal Shahzad, the evidently and thankfully incompetent bombmaker. He was arrested on board a plane headed out of the country, the result of fine detective work in a very short amount of time, but the President was lucky too that the plane had not taken off. Shahzad paid for his ticket with cash at the last minute, which required the airline to send an alert to U.S. officials. Shahzad had been placed on the government’s “no fly” list more than six hours earlier. Yet, he was allowed to board and the plane was getting ready to depart when officials ordered it back and arrested him. How can someone on a “no fly” list, especially someone just put on that list, with all the attendant publicity of the failed Times Square bombing, be allowed to board? Where was the glitch? Someone needs to be fired. If that plane had taken off and Shahzad was today appearing on web videos from Pakistan, Obama’s poll numbers would be tanking. And properly so.

If the oil catastrophe in the Gulf shows the need for more government oversight of safety measures at drilling sites, the near-catastrophe at JFK Airport shows the need to take a long look at the Department of Homeland Security and its procedures. Billions of dollars have been thrown at the agency since 2001, which sometimes produces innovative results and sometimes produces a lack of accountability.

For the President, there is a need to communicate with the American people about the nature of these different problems. His sometimes hyper-enthusiastic fans need to be reminded that there are problems he cannot fix, objectives that no amount of government oversight can achieve, questions for which the government cannot or should not offer an answer. And, he needs to remind his equally hyper-enthusiastic opponents, that there are roles and tasks only the government can perform, some problems that can be solved, some challenges that must be faced whether we expect to succeed or not. They do not really teach Civics in high school anymore, so the President must do so. Otherwise, his presidency could rise and fall with the tides in the Gulf or the preparedness and competence of an airport security official.