It was the silence heard around the political world.

Republican presidential candidate Herman Cain talks to reporters before greeting supporters at a fund raising event before an NFL football game between the Green Bay Packers and the Minnesota Vikings Monday, Nov. 14, 2011, in Green Bay, Wis. (AP Photo/Mike Roemer)

Cain and his campaign have downplayed the controversy, insisting that he was operating on four hours of sleep and that he paused “so I could gather my thoughts”.

But even as they sought to minimize the damage, more clips from the Journal-Sentinel interview came out Tuesday — including one in which Cain said he offered Henry Kissinger the job of secretary of state in his administration but was rebuffed.

But later Tuesday, Cain spokesman J.D. Gordon said that Cain never asked the elder statesmen such a thing and was kidding in the video.

Listing the rest of his Cabinet dream team, Cain also said he had conversations with the likes of former Bush U.N. ambassador John Bolton and would like to see House Budget Committee Chair Paul Ryan (R-Wis.) as a member of a Cain administration along with Sen. Jim DeMint (R-S.C.).

“My Administration will a majority of business people as well as some seasoned office-holders who are not afraid to challenge the status quo,” Cain said.

“Cain’s fundamental problem is being an outsider has its advantages but unless he can display sufficient grasp of the issues, his support will hit a ceiling,” said Ari Fleischer, a former press secretary for President George W. Bush. “The weaker his grasp, the lower the ceiling and he’s starting to bump his head against it.”

The Libya flub — and, to be clear, it was a flub — could not have come at a worse time for Cain.

New polling from the Washington Post-ABC News shows that Cain’s negative ratings among Republicans have more than doubled since mid-October. And, a new CNN survey showed Cain dropping 11 points in a hypothetical national Republican primary ballot in less than a month.

That free-fall is almost certainly due to his scattered response to sexual harassment from a series of women Cain worked with when he headed the National Restaurant Association in the 1990s. But, this latest episode certainly won’t help him turn things around.

“It is yet another foreign policy stumble for Cain,” said Republican consultant Mike Murphy. “The questions about his qualifications for the job will only rise higher now.”

(Murphy did add, however, that Cain eventually “landed on a clumsy but real argument a lot of foreign policy people have made about not knowing enough about the long term goals and true composition of the Libyan opposition. But it was long wobbly route to get there.”)

Murphy’s right. Cain’s Libya non-answer didn’t happen in a vacuum. It comes after a somewhat overlooked performance in an early May presidential debate in South Carolina where Cain said he didn’t have a plan about what to do in Afghanistan because “it’s not clear what the mission is.” And Cain also struggled to lay out a foreign policy vision in a sitdown with NBC’s David Gregory on “Meet the Press”.

In the same way that Perry’s inability to name the third federal department he would eliminate as president (Energy!) proved to many people that he wasn’t ready for primetime, Cain’s seeming cluelessness about Libya plays into the already-in-place storyline that he doesn’t know much about much aside from his “9-9-9” tax reform plan.

“It turns out that ‘Cain unplugged’ is very low wattage,” said California-based Republican consultant Rob Stutzman. “One would think the 435th smartest member of Congress would have a shot to take him in a foreign policy debate.”

Viewed broadly, the grinding presidential primary process — non-stop travel to early states, a cornucopia of debates, relentless fundraising — is meant to serve as a gauntlet that anyone who wants to be president must run.

Its physically and mentally challenging, and forces candidates to not only think deeply about the right way forward for the country but also react to the ever-changing political landscape. In short, it’s a dry run for what actually being the president of the United States is like.

Some candidates embrace that challenge and prosper. Others shrink from it — or just plain wilt.

The last three weeks of Cain’s campaign — not just his inability to find a coherent answer on the U.S.’s approach to Libya or the harassment allegations against him but also his odd responses to both controversies — have rightly raised a red flag for many Republicans wondering whether he is up to the job he is seeking.

“Cain is struggling,” said former Indiana Republican Rep. Chris Chocola who now heads the conservative Club for Growth in an interview on MSNBC’s “Daily Rundown” Tuesday morning. “I think he is not surviving the glare of the spotlight right now.”

Will Cain’s most recent flub cause more damage to his chances to win the nomination? Or does he still have time to recover from perception he has a “low ceiling?” Weigh in on Twitter using #Caindamage