You need only to look at the circus (apologies to circus owners everywhere) in the District over the debt ceiling or the unemployment rate or the state of the Middle East non-peace, non-talks to understand that President Obama’s veneer of competency has rubbed off. Now there is a legitimate question: Is he in over his head? His incessant speechifying and lack of policy production (on the debt, on tax reform, on immigration) suggest that he has not much to offer beyond shopworn oratory. He issues proclamations (internationally or at home) that are routinely ignored, and he seems to be trying to catch up to the news rather than shape events.

The Republican presidential candidates won’t have to strain to make the argument that Obama hasn’t performed and lacks the ability to perform in the future. It is not simply the economy, but also his seeming inability to marshal support, conceive and shepherd policy through the congressional labyrinth and restore a sense of optimism. Yes, it does seem rather Jimmy Carterish. In other words, he doesn’t seem so much like a leader anymore.

This creates challenges and opportunities for each of the Republican candidates. It demands a certain aura of steadiness and the ability to rise above the petty snipes and jabs thrown by opponents. Sen. John McCain (R-Ariz.) didn’t have it in 2008; Ronald Reagan convinced voters in 1980 he did.

This is part of the intangible qualities of leadership — steadiness, firmness and seriousness. The public, I would suggest, mistook Obama’s personal remoteness for largeness of vision, spirit and competency.

A reader wrote in yesterday to ask why it seemed that Tim Pawlenty didn’t have that ability to project authority. You can point to small tics or voice quality, but there is something too anxious, too rushed that comes across as if he’s got 15 minutes of material for a 10-minute book report.

Because Texas Gov. Rick Perry has not been visible and scrutinized on the national stage, it’s hard to see how he will hold up in the months ahead should he enter the race. In an interview with me early this year, he came across as solid and in command of his facts.That’s a far cry, however, from a campaign in which TV reporters grill you, the scrum of print reporters pepper you with questions and the debaters you face are experienced and prepared. If his rap is “cockiness,” his challenge is to project some depth and seriousness.

Rep. Michele Bachmann’s greatest challenge in the primary (as opposed to the general election) is to demonstrate that her firebrand conservatism can translate in office into firmness, determination and reliability, rather than undiluted dogmatism that people find unsettling. Her performance in the New Hampshire debate was highly praised because the fiery Tea Partyer came across as hyper-prepared and focused. She will need to demonstrate that week after week.

As for Mitt Romney, he’s got the advantage of an executive bearing. Not surprising for a former Bain executive and governor, he is not easily rattled. Of all the candidates, he is the one, I am sure, about whom his campaign team worries about the least in interviews and impromptu speeches. He simply isn’t going to make a cringe-inducing error. Some say he’s overly prepared, but the public expects a certain polish in its leaders. The rap last time around was that he was too programmed, too robotic. So far he does seem a bit more relaxed and comfortable in his own skin. He’ll have to show he is also empathetic and can not only command but also relate to voters.

There is no single model of what a presidential candidate looks or sounds like. But the successful ones understand that it is not simply experience or position on issues that wins the day. It is the ability to convince others that this person has the seriousness of purpose and steel in the spine to tackle whatever issues come his or her way in the Oval Office. It is often only over the long course of a campaign that voters can determine who’s got it and who doesn’t.