First, Herman Cain couldn’t stop talking about the sexual harassment allegations — or changing his story. Then he started accusing Texas Gov. Rick Perry’s campaign of “leaking” the information. And all the while he called the media and any critic who dared to raise the subject racist. Now he bellows at the media that he’s done talking. He's getting back on message, he instructs the media.

The media and debate moderators should not be bullied into quietude. There are legitimate questions, many of them, to be asked. Why did he initially deny a settlement? With regard to two claims that settled for $80,000, one of which involved advances over several months, does he really not recall the particular behavior at issue? Why did he leave the National Restaurant Association before his contract was up? Why shouldn’t voters consider this in evaluating his executive skills? What in particular is inaccurate in Politico’s reporting? Does he think he responded last week in an appropriate and effective manner? At the debate in Texas on Saturday, he said he didn’t expect the media “flyspecking”; does he not think that voters have a right to know just about everything about a presidential candidate? Why has his wife not spoken out?

Cain can huff and puff all he likes. He can refuse to answer questions. But that doesn’t mean the questions shouldn’t be asked. The debates are not a time for allowing candidates to stay huddled in their comfort zones. The voters have every right to see them pushed on their experience and character, not merely on their positions on the issues.

If the media stop asking about a legitimate topic (one that, for example, Mississippi Gov. Haley Barbour, the former Republican National Committee chief, said is entirely legitimate), they abdicate their responsibility. Republicans complain that the media never vetted Barack Obama fully. They are right, but that’s no excuse to repeat the error and let another candidate slip by without a full accounting of his past.

The next debate, hosted by Maria Bartiromo of CNBC, is Wednesday. I’m sure she’ll ask about the candidates’ tax plans. She should grill Perry on his crony capitalism and views on property rights. She should ask Newt Gingrich about his leadership failures as speaker of the House. She needs to delve into Mitt Romney’s claims about job creation both as governor and at Bain Capital. And, yes, she should explore Cain’s liabilities as well, including lack of familiarity with China’s nuclear capability, his inability to answer questions about his own tax plan and, yes, a pattern (three is a pattern) of alleged sexual harassment and failure to be straightforward with the American people.

If Cain can’t hack it, he should go back to the book tour. If he wants to be the nominee, he needs to show voters he can take the heat. Otherwise, he’s got no business being in a presidential race.