ROCHESTER, Mich. – With under two months before the first votes are cast in the Republican presidential primary, the GOP candidates gathered for a debate in a state that has suffered gravely during the nation’s economic recession – but what stole the show were the varying fortunes of the two candidates that pose the biggest threat to Mitt Romney’s chances of securing the nomination: Herman Cain and Rick Perry.

While the former has surged in the polls and continues to enjoy support despite new allegations of sexual harassment, the latter has plunged in recent months, even falling outside the top three in polls. Those trends were on full display here at Oakland University as the crowd voiced their strong support for Cain despite the allegations against and sat silently - stunned - as Perry flailed away, unable to name the third federal agency that he said he would eliminate as president.

“It’s three agencies of government when I get there that are gone - Commerce, Education and the um, what’s the third one there?” Perry said. “Let’s see. Oh five – Commerce, Education and the um, um.”

“EPA?” suggested his rival, Rep. Ron Paul, R-Texas.

“EPA, there you go,” replied Perry, before correcting himself.

“No sir,” he said, “we were talking about the agencies of government [that should be cut]. The EPA needs to be rebuilt.”

“But you can’t name the third one?” asked CNBC moderator John Harwood of Perry.

“The third agency of government I would do away with - the Education, the uh, the Commerce and let’s see, I can’t the third one,” Perry admitted. “I can’t.”

The cringe-worthy moment was so bad that the Texas governor then sighed and said simply, “Oops.”

Perry did not let it go there, noting later that the agency that had slipped his mind was the Department of Energy.

While Perry flopped, Cain’s fortunes could not have been more different. Earlier in the debate, when CNBC’s Maria Bartiromo started to ask Cain about the sexual harassment allegations, the crowd at Oakland University booed loudly.

“Mr. Cain, the American people want jobs, but they also want leadership. They want character in a president. In recent days, we have learned that four different women have accused you of inappropriate behavior. Here we’re focusing on character and on judgment,” Bartiromo said, prompting fierce boos from the audience, protesting the question they knew was coming.

“You’ve been a CEO,” she continued. “You know that shareholders are reluctant to hire a CEO where there are character issues. Why should the American people hire a president if they feel there are character issues?”

“The American people deserve better than someone being tried in the court of public opinion based on unfounded accusations,” Cain said to huge cheers from the crowd. “And 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 probably — there are thousands who would say none of that sort of activity ever came from Herman Cain.”

“This country’s looking for leadership. And this is why a lot of people, despite what has happened over the last nine days, are still very enthusiastic behind my candidacy,” he said. “Over the last nine days, the voters have voted with their dollars, and they are saying they don’t care about the character assassination. They care about leadership and getting this economy growing and all of the other problems we face.”

Since the allegations were first leveled against him late last month, Cain has raised millions of dollars from supporters. While the former Godfather’s Pizza CEO still trails far behind Romney and Perry in the GOP money race, he continues to sit atop the polls less than two months before the first votes are cast in the primary process that starts in Iowa in early January.

According to a USA Today/Gallup survey released earlier this week, Cain and Romney are tied with 21 percent support among Republicans and Republican-leaning independents.

Romney, who was born in Detroit just down the road from the debate site, had to respond to questions about his opposition to the federal bailout for Detroit automakers General Motors and Chrysler. President Obama’s re-election campaign has emphasized Romney’s stance in recent months, saying more than a million jobs were saved by the White House intervention.

“I have seen this industry and I have seen this state go through tough times,” Romney said. “And my view some years ago was that the federal government, by putting in place CAFE requirements that helped foreign automobiles gain market share in the U.S., was hurting Detroit. And so I said, ‘Where is Washington? They are not doing the job they ought to be doing.’ My view with regards to the bailout was that whether it was by President Bush or by President Obama, it was the wrong way to go. I said from the very beginning they should go through a managed bankruptcy process, a private bankruptcy process.”

“My plan - we would have had a private sector bailout with the private sector restructuring and bankruptcy with the private sector guiding the direction as opposed to what we had with government playing its heavy hand,” said the former Massachusetts governor.

Economic issues remain crucial to this state, where the unemployment rate sits above 11 percent, more than 2 percent higher than the national average. The nation’s financial situation remains tenuous as problems in Europe continue to cause concern on Wall Street and Main Street. The Dow Jones Industrial Average today dropped more than 400 points, a plunge that comes amid growing concerns over Italy’s financial crisis.

According to a new Univision/Latino Decisions poll released Tuesday, among all voters nationwide, 74 percent said the most important issue in how they will pick a candidate to support will be jobs and the economy. At the Michigan debate, the ninth thus far, the candidates outlined their proposals to generate economic growth.

“My proposal is the only one that solves the problem by throwing out the current tax code, which has been a mess for decades, and we need to put in something different that I proposed, 9-9-9,” Cain said. “It satisfies five simple criteria. It is simple. The complexity costs us $430 billion a year. It is transparent. People know what it is. There are thousands of hidden sneak-a-taxes in the current tax code. That’s why I want to throw it out. It is fair. The reason it’s fair is because of the definition in Webster, which says everybody gets treated the same. All businesses get treated the same, not having Washington, D.C., pick winners and losers. This is why I have proposed a bold plan of 9-9-9 - 9 percent business flat tax, 9 percent tax on personal income, and a 9 percent national sales tax. It treats everybody the same. And it will boost this economy.”

As the candidates head out of Michigan before their next debate in South Carolina on Saturday night, Cain will do so feeling optimistic that he can overcome the harassment allegations and continue to challenge Romney for the nomination. Perry, meanwhile, may wish that he had followed through on his campaign’s threat to skip some of the debates in the primary’s crowded calendar.

After Perry’s gaffe tonight, Romney’s spokesperson Ryan Williams tweeted simply, “Um, wow.”

Romney senior advisor Eric Ferhnstrom told reporters that there’s “nothing I could say that could darken the night Rick Perry has had.”

Matthew Jaffe is covering the 2012 campaign for ABC News and Univision.