Texas Gov. Rick Perry made the worst stumble of the presidential campaign on Wednesday, struggling awkwardly to remember the name of a third federal agency he would eliminate if he became president.

At a time when Perry’s team was hoping desperately for a breakout, or at least mistake-free, performance to revive his ailing campaign, the governor’s gaffe could well do lasting damage. Perry’s performance raises more questions about his ability to compete at a time when GOP voters are looking for someone to go toe-to-toe against President Obama in 2012.

“It is three agencies of government when I get there that are gone,” he said, beginning to lay out one of the staples of his stump speech. “Commerce, Education, and the — what’s the third one there? Let’s see,” Perry said.

“Commerce and, let’s see,” he continued. “I can’t. The third one, I can’t. Sorry. Oops.”

After the debate, Perry’s campaign advisers sought to contain the damage by describing the stumble as “a human moment” and “authentic.” But in a rare appearance in the media filing center after the debate, Perry acknowledged the gravity of the mistake.

“Yeah, I stepped in it, man,” he said. “Yeah, it was embarrassing. Of course it was. But here’s what’s more important: People understand that our principles, our conservative principles, are what matter, not a litany of agencies that I think we need to get rid of.”

He repeated that mantra Thursday morning during interviews with several nationally televised news programs. “If anybody’s looking for the slickest politican or the smoothest debater, I readily admit I’m not that person,” Perry told Fox & Friends. “But my conservative values have led one of the most influential states in the nation.”

One NBC’s “Today” show, Perry said, “One error is not going to make or break a campaign. We’re going to continue talking about the challenges facing this country.” 

The debate was brighter for Herman Cain, a Georgia businessman whose campaign has been consumed for the past 10 days by accusations of past sexual harassment.

In the debate’s opening moments, Cain was asked to assess whether voters should judge his character before deciding whether to send him to the White House. In response, he lashed out at his accusers, dismissing the allegations as “character assassination.”

“The American people deserve better than someone being tried in the court of public opinion based on unfounded accusations,” the former Godfather’s Pizza executive said, prompting cheers from the audience. “I value my character and my integrity more than anything else, and for every one person that comes forward with a false accusation, there are thousands who would say none of that sort of activity ever came from Herman Cain.”

Against the backdrop of global economic volatility, the eight Republican presidential candidates who took the stage Wednesday at Oakland University sought to prove they have the ideas, know-how and leadership to pull the United States out of its worst period of economic stagnation since the Great Depression.

On a day when the Dow Jones industrial average fell 3.2 percent, the GOP contenders addressed a range of financial issues, including the European debt crisis, taxes, manufacturing tax credits, housing, health care and the role of government bailouts. Although they outlined some differences with one another — notably on tax policy — they spent more time united in their opposition to Obama and their agreement that lowering taxes, eliminating regulations and downsizing government would turn the economy around.

“Markets work,” former Massachusetts governor Mitt Romney said. “When you have government play its heavy hand, markets blow up and people get hurt.”

The debate, co-sponsored by CNBC and the Michigan Republican Party, contrasted sharply with the last such forum, held in Las Vegas in October, when the candidates ganged up on one another in a series of attacks more intense than in any of their previous appearances.

On Wednesday, the contenders even declined to go after the two front-runners, Romney and Cain. The job of asking tough questions fell to the two CNBC moderators, Maria Bartiromo and John Harwood, in a fast-paced and at times confrontational program that took a deep dive into the nation’s economic challenges and what the federal government should do to address them.

The debate, held about 30 miles north of Detroit, provided a fitting venue for an in-depth exploration of economic issues, given Michigan’s high unemployment rate, its struggling automobile industry and its status as ground zero for the decline of manufacturing in the United States.

One of the few areas in which the candidates displayed clear contrasts was on taxes. Cain and Perry proposed to flatten the tax code to a single rate for everyone, but Romney, when pressed, said he would simplify but not flatten the code.

Rep. Michele Bachmann (Minn.), meanwhile, tried to stand out with a proposal that would require every worker to pay taxes, however modest.

“I have everyone paying something because everyone benefits by this magnificent country. So even if it means paying the price of two Happy Meals a year, like $10, everyone can afford to pay at least that,” Bachmann said. “And what it does is create a mentality in the United States that says that freedom is free. But freedom isn’t free. We all benefit. We all need to sacrifice. Everybody has to be a part of this tax code.”

Cain and Romney said that the United States should resist all calls to bail out affected banks, whether domestic or foreign.

“Europe is able to take care of their own problems,” Romney said. “We don’t want to step in and try to bail out their banks and bail out their governments. My view is no, no, no. We do not need to step in to bail out banks in Europe or even banks here that have Italian debt.”

Romney has delivered poised and confident debate performances, but he has fallen short in convincing voters that he would be a passionate leader with bold ideas to transform the way Washington works. He was forced to address that issue early on in Wednesday’s debate, when Harwood asked him to explain why Republicans should vote for him “with a record like that of seeming to be on all sides of the issue.”

“I think people understand that I’m a man of steadiness and constancy,” Romney said. “I don’t think you’re going to find somebody who has more of those attributes than I do.”

Romney went on to blame Democrats for the narrative that he is a flip-flopper.

“I think it’s outrageous that the Obama campaign continues to push this idea when you have in the Obama administration, the most political presidency we’ve seen in modern history,” he said. “If I’m president of the United States, I will be true to my family, to my faith, to my country.”

And for the other contenders, who have had difficulty making early impressions on voters, Wednesday’s debate offered a new chance to build momentum — or, in some cases, simply survive.

Former Utah governor Jon Huntsman Jr., who has been one of the more aggressive candidates in attacking Romney on his evolving positions on some key issues, tried to jump-start his candidacy by rooting the night’s debate in the real problems that Americans face each day.

Former House speaker Newt Gingrich (Ga.) has seen his support grow in recent surveys — so much so that he had a new position on Wednesday, closer to center stage and next to Romney.

Michigan was a backdrop that quickly put Romney in the hot seat despite the fact that he was born and raised a few miles down the road. He has been the subject of a coordinated assault by Democrats on his opposition to the 2008 federal bailouts for U.S. auto companies. Romney has tried to explain his position by saying he favored a structured bankruptcy for the nation’s Big Three auto companies — and on Wednesday he did so again.

“Whether it was by President Bush or President Obama, it was the wrong way to go,” Romney said. “I said from the very beginning they should go through a managed bankruptcy process.”