Since the beginning — which was all of seven weeks ago — Jon Huntsman Jr.’s campaign has promised something completely different.

The campaign has offered video tidbits of a mystery man, a father of seven, a lover of rock music and a diplomat on a dirt bike who is no ordinary politician. The operation launched a sleek, clean Web site that looks nothing like those of other candidates.

Then the big reveal: Huntsman took the stage at Liberty State Park Tuesday and sought to deliver a careful message, one that included a different take from his Republican rivals on President Obama.

“I respect the president of the United States,” said Huntsman, who served as Obama’s ambassador to China until late April. “He and I have a difference of opinion on how to help a country we both love. But the question each of us wants the voters to answer is who will be the better president, not who’s the better American.”

A self-described “margin of error” candidate, Huntsman entered the race for the White House Tuesday as the biggest wild card in the 2012 field. His long list of credentials and his fundraising ability could quickly catapult him to top-tier status. Or his unconventional approach and conciliatory message could relegate him to a footnote in the race.

Which way it goes is likely to turn on whether Huntsman, likened to Superman by a speaker at a New Hampshire stop Tuesday, can step into the lofty promises and expectations of the campaign that has been created around him, whether he can transform his carefully crafted man-of-the-moment narrative into momentum and crowds.

GOP strategist Ron Bonjean noted the risk of heightened expectations, particularly Huntsman’s choice to announce his candidacy across the water from the Statue of Liberty — the same spot where Ronald Reagan launched his general election campaign in 1980.

“The announcement of the speech backdrop created such a hype that it made it virtually impossible for Huntsman to capture lightning in a bottle with his performance,” Bonjean said.

Reagan historian and GOP strategist Craig Shirley offered a similar critique. “Frankly, the moment was bigger than Huntsman,” Shirley said after the speech. “Huntsman did not tell the viewer why he was running, what he would do if elected and why he was an acceptable alternative to President Obama.”

In making his announcement, Huntsman outlined his aspirations for the nation and cited his experience as governor in explaining how he would “reignite the powerful job-creating engine of our economy.”

“We did many of these things in Utah when I was governor. We cut taxes and flattened rates. We balanced our budget. . . . When the economic crisis hit, we were prepared,” Huntsman said. “We proved that government doesn’t have to choose between fiscal responsibility and economic growth.”

On the question of whether he can fulfill the narrative of his campaign, the evidence so far is mixed.

Huntsman’s own aides have openly wondered whether he can evolve from a candidate who connects in small rooms to one who can carry large crowds. The concern was underscored last week when Huntsman mentioned on the trail that he was tired. A few days later, he cancelled a scheduled appearance at the Republican Leadership Conference in New Orleans because he was too sick to travel.

His campaign is also off to an uneven start. Staffers, many of whom never met Huntsman before he returned from China, spelled his name wrong on press passes handed out at Tuesday’s ceremony, inserting an “h” in Jon. Reporters spotted that the sleek new Web site included the wrong phone number — 123-456-7890 — and address — 123 Main Street, Charlotte, N.C. — for the campaign. The headquarters is actually on Orange Avenue — in Orlando.

A critical question will be how Huntsman chooses to articulate his relationship with Obama, and their differences. With others in the GOP field competing to be the loudest critic of the president, Huntsman has limited his criticism so far mostly to the president’s approach to foreign policy and the economy.

In his announcement speech, Huntsman alluded to Obama’s 2008 campaign theme by saying the nation needed “leadership that knows we need more than hope, leadership that knows we need answers.”

Obama aides are casting Huntsman, who was appointed ambassador by Obama in May 2009, as a changed man.

“He was encouraging on health care; he was encouraging on the whole range of issues,” said Obama strategist David Axelrod, in a CNN interview. “And if he had suggestions on the economy, he had an excellent opportunity to suggest them, when we were all together in China.”

In his speech, Huntsman said he intends to keep his criticism respectful, steering clear of “corrosive” hyperpartisan debate.

“We will conduct this campaign on the high road,” Huntsman said. “I don’t think you need to run down someone’s reputation to run for president.”

Huntsman is likely to spend the next several days laying out his vision for a new direction on Afghanistan and job-creation as he embarks on a tour to South Carolina, Florida, Utah and Nevada.

Huntsman’s aides are touting his fiscally conservative, pro-business record while governor of Utah, as well as his support of strict abortion laws.

And they argue that he is indeed different.

“He is totally comfortable with who he is, he is an authentic person, and he is the kind of guy who can lead our party to new heights demographically and philosophically,” said John Weaver, Huntsman’s top strategist. “Here is a guy who loves music, wanted nothing more than to be a rock star, loves motorcycles and can interact with everyone, and for a Republican, that is new and refreshing.”