The candidate insists his dearth of specific knowledge is no problem -- that there are plenty of people to advise him. Actually, they'll dominate him.
One of the most trenchant criticisms of Herman Cain I've yet seen comes from James Poulos in his latest column at The Daily Caller, where he muses on how absurd it is that "a political outsider fields basic questions about his approach to fundamental policy matters by invoking the wise counsel of expert bureaucrats." It really is something when you think about it. The reason a political outsider is attractive to some voters is the notion that the existing system is broken. The politicians and the bureaucrats always conspire to flout the will of the people. But asked what he'd do about a specific policy issue, Cain often responds with some variation on the idea that he'll supply the general principles that guide policy, and leave the rest to better informed advisers.
Does he understand that the experts are themselves members of the establishment? No, not on every issue, but on a lot of them with which a president must grapple. It's naive to imagine that a leader with no detailed knowledge of policy, foreign or domestic, can summon to the Oval Office a bunch of wonks who'll defer to whatever principled framework is laid down. A wonk briefing a man who knows as little as Cain will inevitably influence policy by framing questions in particular ways, exercising discretion over which options he presents, failing to be an honest broker among ideas. A populist movement more mature than the Tea Party would understand that the ideal vehicle to shake up the system and challenge entrenched behaviors is someone knowledgeable enough to call out experts when their version of reality is incomplete.