Could Herman Cain be the Republican nominee for president? The idea sounds preposterous but seems increasingly likely. Cain, who has never held political office, has policy experience limited to serving on the Kansas City Federal Reserve Board and representing the interests of fast food chains as president of the National Restaurant Association. His biggest success is boosting sales of the country’s ninth-largest pizza chain, and his current job is hawking books and giving paid speeches as a motivational speaker. On crucial subjects such as foreign policy, he demonstrates startling ignorance or a simple unwillingness to even take a position. On domestic subjects that don’t require detailed policy knowledge, such as what he thinks of abortion, Cain manages to contradict himself and flip-flop, often within the same interview.

And yet, here he is, tied with or leading Mitt Romney in the national polls, and ahead in Iowa and South Carolina. Statistical analyst Nate Silver of the New York Times, whose predictions on the last election were consistently the most accurate, cautions that while he doesn’t know what Cain’s chances are, “I do know what an analyst should not do: he should not use terms like ‘never’ and ‘no chance’ ” when applied to Mr. Cain’s chances of winning the nomination.” Silver adds: “I think it is quite arrogant to say that the man leading in the polls two months before Iowa has no chance.”

If Cain really could be the Republican nominee, it’s time to interrogate his bizarre and vague platform. Here are some questions reporters with the opportunity should ask him.

§ You are fond of boasting about how you lived the American Dream by rising from a poor family to make a lot of money. You also call for brutally cracking down on illegal immigration from Mexico, most notably by saying that you would put an electrified fence topped with barbed wire on the border and possibly send armed troops to guard it. Why do you think that Mexicans who come here to work low-paying jobs are different than your parents, seeking a better life for themselves and their children?

§ The nonpartisan Tax Policy Center says your “9-9-9” tax reform proposal will raise taxes on 84 percent of Americans. It will raise taxes on lower- and middle-income Americans, by taxing sales and eliminating the standard deduction, while cutting taxes on the wealthy by lower income tax rates and eliminating taxes on inheritance and capital gains. The TPC found that your plan would raise taxes on everyone making less than $100,000 and raise taxes by more than 10 percent on everyone making less than $40,000. It would cut taxes on people making more than $100,000 and provide a huge tax cut of over 30 percent to people making more than $1 million per year. Why do you think this is fair? Do you think if your parents had to pay higher taxes it would have aided your social mobility?

§ Under 9-9-9 payroll taxes would be eliminated. How would you determine a person’s Social Security benefits? How would protect Social Security and Medicare funding from being raided when there is no separate revenue stream for them?

§ You’ve called for the repeal of the Affordable Care Act. Do you think the 50 million Americans without health insurance deserve to get health insurance? If so, how exactly would you provide it for them? How would fix the unsustainable upwards trajectory of healthcare spending, which has exceeded economic growth in every recent decade? Please note that tort reform and selling insurance across state lines is not an acceptable answer. Neither of those proposals would guarantee that insurance will be sold to people with prior conditions or modest means, nor does the cost of doctors’ malpractice insurance account for anywhere near the majority of the increase in healthcare spending.

§ You say 9-9-9 will be revenue neutral. If so, how exactly do you propose to close our budget deficit? Inevitably, any method of balancing the budget without increased revenues will require cuts to domestic programs that benefit the poor. Why do you think poor people should pay more in taxes while getting less in services from the government?

§ You say 9-9-9’s virtue is its simplicity. But you’ve already introduced two exceptions to it: an exemption from the sales tax for goods manufactured domestically, and an exemption for low-income communities. How will you compensate for the lost revenue? How do you respond to the logical inference that your plan would become just as riddled with loopholes over time?

§ Like Michele Bachmann and Ron Paul, you’ve called for eliminating the Environmental Protection Agency. Like both of them, you’ve also neglected to explain who would enforce laws such as the Clean Air Act and Clean Water Act in the EPA’s absence. So, who would do it? Or do you not think we need clean air and water?

§ You’ve refused to take a position on American troop levels in Afghanistan and ridiculed the notion that you should know the name of the President of “Ubeki-beki-beki-beki-stan-stan.” Why don’t you think that the US president should know the name of Islam Karimov, the president of Uzbekistan, especially since Karimov is a brutal dictator in the strategically important region of Central Asia? Why don’t you think the American people should know where a candidate for president stands on our foreign war in Afghanistan?