For a man who won office talking about change we can believe in, Barack Obama can be a strangely passive president. There are a startling number of occasions in which the president has been missing in action - unwilling, reluctant or late to weigh in on the issue of the moment. He is, too often, more reactive than inspirational, more cautious than forceful.

Each of these instances can be explained on its own terms, as matters of legislative strategy, geopolitical calculation or political prudence.

He didn't want to get mired in legislative details during the health-care debate for fear of repeating the Clinton administration's prescriptive, take-ours-or-leave-it approach. He doesn't want to go first on proposing entitlement reform because history teaches that this is not the best route to a deal. He didn't want to say anything too tough about Libya for fear of endangering Americans trapped there. He didn't want to weigh in on the labor battle in Wisconsin because, well, it's a swing state.

Yet the dots connect to form an unsettling portrait of a "Where's Waldo?" presidency: You frequently have to squint to find the White House amid the larger landscape.

This tough assessment from someone who generally shares the president's ideological perspective may be hard to square with the conservative portrait of Obama as the rapacious perpetrator of a big-government agenda. If the president is being simultaneously accused of overreaching ambition and gutless fight-ducking, maybe he's doing something right.

Maybe, or else Obama has at times managed to do both simultaneously. On health care, for instance, he took on a big fight without being able to articulate a clear message or being willing to set out any but the broadest policy prescriptions. Lawmakers, not to mention the public, were left guessing about what, exactly, the administration wanted to see in the measure and where it would draw red lines.

That was not an isolated case. Where, for example, is the president on the verge of a potential government shutdown - if not this week, then a few weeks from now?

Aside from a short statement from the Office of Management and Budget threatening a presidential veto of the House version of the funding measure, the White House - much to the frustration of some congressional Democrats - has been unclear in public and private about what cuts would and would not be acceptable.

By contrast, a few weeks before the shutdown in 1995, Clinton administration aides had dispatched Cabinet members and other high-ranking officials to spread the message that cuts in education, health care and housing would harm families and children. Obama seems more the passive bystander to negotiations between the House and Senate than the chief executive leading his party.

He performs best on a stage that permits the grandest sweep. He rises to the big occasion, from his inspiring introduction to the public in his 2004 Democratic convention speech to his healing words in the aftermath of the Tucson shootings.

The president has faltered, though, when called on to translate that rhetoric to more granular levels of specificity: What change, exactly, does he want people to believe in? How, even more exactly, does he propose to get there? "Winning the future" doesn't quite do it.

My biggest beef is with the president's slipperiness on fiscal matters. Obama has said he agrees with some of his fiscal commission's recommendations and disagrees with others. Which ones does he disagree with? I asked this question the other day of Austan Goolsbee, the chairman of the Council of Economic Advisers.

Here's what I got: "The view espoused by some of the . . . commission that we ought to do Social Security 100 percent off of benefit cuts for sure he doesn't agree with." But of course, the plan that 11 of the commission members endorsed did nothing of the sort.

I was unfair to Goolsbee because I asked him a question he didn't have the leeway to answer. You can't blame the aide for ducking when the boss fudges.

Where's Obama? No matter how hard you look, sometimes he's impossible to find.