Ordinary people may not know much about public affairs, but it is wrong to assert, as one Political Science professor from a Big Ten university allegedly said shortly after the 2010 elections, voters are "pretty damn stupid."

Ignorance means a lack of knowledge about a topic. Stupidity refers to a lack of mental capability. Political ignorance should not be excused because it is deleterious to popular government. Nevertheless, ignorance can be rectified, at least a little. Cognitive ability is mostly set at birth.

Doubts about citizens' political IQs are as old as the Republic. Accusations of grassroots political ignorance are not the exclusive purview of any political party or ideological orientation. Usually, charges that "voters are idiots" are levied by the losing side after an election.

Several of the responses to my earlier article asserting that most Americans don't know much about politics made this type of comment about Obama voters. Yes, some people who voted for him were ignorant. But don't, as a famous politician once said in another context, "mis-under-estimate" some in this electorate. (Some comments on the earlier article didn't.)

In war -- and make no mistake, American politics are much like war these days -- he/she who underestimates the foe does so at his/her own risk.

Sometimes supporters of a political issue or personality will doubt opponents' intelligence. The cover story of the January 23, 2012 issue of Newsweek, for example, was "Why Are Obama's Critics So Dumb?" A review of Mark Levin's Ameritopia in The Chronicle of Higher Education had, as a partial subtitle, "Just How Dumb Can Political Philosophy Get?"

It is easy to dismiss accusations of voters' or political opponents' stupidity as sour grapes. It is entirely another matter, however, when large portions of America's ruling class disparage citizens' mental competence. Pollster Scott Rasmussen estimates that approximately three-fifths of America's ruling class believe that the typical citizen is a dolt. If majorities of the ruling class disparage citizens' political IQs, will they be tempted to substitute their opinions for those of the great unwashed?

It would not be deleterious to popular government if the ruling class and the rest of us had (at least reasonably) similar opinions on policy issues. In that case, if -- believing members of what Angelo Codevilla calls "the country class" are political dumb-bells -- the ruling class substituted their own opinions, policy would still be pretty much what public opinion wishes.

Alas, there is a gulf between the policy opinions of the ruling class -- estimated to be about 7-14% of the population -- and the country class -- alleged to be 55-75% of the populace. (These are Rasmussen's estimates, although the terms are Codevilla's.) On policies such as spending, taxation, abortion, government bailouts, crony capitalism, and immigration, there are gaps between the two camps' opinions. On these and many other issues, the ruling class's opinions are usually to the left of those of the country class.

Thus, if the ruling class substitutes its opinions for those of the country class -- some think this is happening more and more -- government policy bears scant resemblance to what most citizens want. Is it any wonder that fewer people trust the federal government than at any time in the last half-century, Congress is held in low regard, and large majorities believe the country is on the wrong track?

Let us return to whether ignorance and stupidity are birds of a feather. If one thinks they are, then the sooner we adopt a version of "guided democracy," or some such, the better. The New York Times columnist Paul Krugman praised Communist China's government on these grounds. At the very least, we should settle for some version of the nanny state, where those who are smarter than we idiots tell us how to live, and then pass laws to insure we do just that. Some, like David Harsanyi, think we've already gone down that road.

But are Americans who are politically ignorant are also stupid? Some are, of course. Many, however, are not.

Even the Constitution's authors, who were no friends of mass democracy, trusted the common sense of the average citizen enough to leave election to the House of Representatives -- which initially had more control over taxes and the national budget than the Senate or the president -- to direct popular vote.

Some may claim my two articles are inconsistent. The first stressed the typical citizen's political ignorance, and mentioned ignorance's unhappy consequence for representative government. This piece seems to come to the public's defense by distinguishing between ignorance and intelligence.

It is not inconsistent to recognize that one's level of political information and her/his mental capacity are partly uncorrelated. Some Obama voters hate America and know enough to realize that he intends to bring this nation down. Some who call themselves "conservative" are at least a couple fries short of a happy meal.

Acknowledging this does not denigrate these self-declared "conservatives" importance to the cause. At the risk of mangling a metaphor, every oar propels the ship.

Nor does recognizing that some opponents are well-informed do anything other than alert one to the importance of a smart strategy.

Common sense is no substitute for knowledge. It can, however, be sufficient to muddle through to a good decision. Andrew Jackson knew that in the 1820s. It's time we caught up with him.