(RNS) Exactly when did President Obama’s words stop meaning anything? He rose to the presidency on the power of words, and now words seem to be his undoing.

After Tuesday’s (June 15) Oval Office speech about the BP oil spill in the Gulf of Mexico, MSNBC commentators who once fawned over this president’s verbiage now shot him down. Chris Matthews compared Obama to Jimmy Carter, and Keith Olbermann called it “a great speech if you were on another planet for the last 57 days.”

Much is being made of Obama’s failure to grasp the difference between campaigning and governing. A candidate’s words are promises to be fulfilled, and the executive’s words are expected to come to pass — or else.

But what if the problem is deeper?

Aristotle’s classic work on rhetoric (persuasive speech) reminds us that there are three necessary elements for words to persuade: logos, pathos and ethos. The speaker’s words must be rational (logos), delivered with sincere passion (pathos) and the words must be consistent with the speaker’s values, life and behavior (ethos).

This president is failing all three tests.

When oil is gushing out of control off the Louisiana coast and human livelihoods and a fragile ecosystem hang in the balance, it is irrational to exploit the tragedy with lofty words about the need for a new national energy policy.

The public is not convinced of the president’s passion, despite his press secretary shifting into hyper-drive to convince us that the president is really, really angry about the oil spill, followed by Obama’s street talk about “kicking some butt” and daddy talk about his daughter wanting to know if he has plugged the hole yet.

A photo of a president dressed in slacks, dress shirt and leather shoes squatting on a beach to sift through the sand was both a lame photo-op and a stark visual reminder that this president is disconnected from the lives of the down-home Louisianans who work the waters for a living.

Suddenly the cool, unflappable candidate is the cold uncaring executive, the candidate whose strength was his transcendence beyond labels. Now he is not everyman, he is no man. He’s gone from connecting to everybody to connecting to nobody.

But there is something else that comes to mind. As a young seminarian, I read a book by Helmut Thielicke titled “A Little Exercise for Young Theologians.” In it, he tells the story of a farm boy who puts on his father’s overalls. They are obviously way too big; it will take a few years before he will grow into them.

The metaphor was designed to encourage the young pastor thrown into a job beyond his current maturity and capability to be honest with himself and his situation, and then to grow into the overalls.

The metaphor fits anyone who takes the Oval Office, because there is no adequate preparation for becoming the leader of the free world. The fact that the overalls are too big is not a partisan metaphor; it is a factual one.

Could it be that Obama can’t speak with authority because deep down he doesn’t know what to do? “If you can’t explain it simply,” Albert Einstein once said, “you don’t understand it well enough.”

Having built his candidacy around messianic themes, the president must either fulfill them or confess that those overalls are too big. He campaigned on problems that he said he had answers for, but like every president, other issues are taking center stage — issues outside his ideological sweet spots, and ones that will define his presidency.

Words that matter originate from the solid core and character of a virtuous, honest person. Whether president or mere mortal, when our words surpass who we are, we must grow into them — or our words will expose and then devour us.

(Dick Staub is the author of “The Culturally Savvy Christian” and the host of The Kindlings Muse (http://www.thekindlings.com). His blog can be read at http://www.dickstaub.com)