If democracy requires an informed citizenry to function well, the United States is in serious trouble. Many Americans are political ignoramuses.

It doesn't take much effort to describe the typical citizen's political ignorance. The Pew Research Center for The People & The Press, for example, has plumbed random samples of the public's public affairs knowledge about twice a year since 2007. The questions have varied in substance and format, but the results have been uniformly dismal. The average correct score is usually just above 50% which, if judged by the usual academic standard --90+% = A, 80-89% = B, 70-79% = C, 60-69% = D, <60% = F -- would be F.

Since people who cannot be contacted or refuse to take part in polls are more politically ignorant than those who do, these are generous estimates of the public's political knowledge. It's estimated that 25% to 33% or more of the adult populace is "missing in action" when poll results are reported. Were these people's ignorance added to poll results, pollsters tell us that the public's grade would be F-.

One particular Pew Research Center poll illustrates the average citizen's paltry stock of political information. Between July 26-29, 2012, the Pew Research Center asked a random sample of adults twelve questions tapping knowledge of the presidential election. Some questions probed knowledge of where the candidates stood on key issues; others plumbed information about the candidates' background. The average score was 6.5 questions right, or 54% of the total. Forty-nine percent got six or fewer questions correct.

If you think a poll from late July is too early in an election year to provide evidence of what people know on Election Day, history tells us not to expect much learning during a campaign. Moreover, partisans pay heed mostly to stories about their preferred candidate; they generally ignore, or largely discount, information about the other candidate(s). Even when information concerns one's preferred candidate, all too often it's "in one ear, out the other."

People need "old" information to help process and retain "new" information. This is known as "the Matthew principle," after the passage in Matthew 25: 29, which asserts, in effect, "the rich get richer and the poor get poorer."

Many individuals cast ballots knowing virtually nothing about candidates and where they stand on major issues, their country's history and political institutions, the ideals that have motivated earlier generations, and the likely consequences of their vote. These "low-information voters" cast ballots mostly on the basis of race, ethnicity, gender, sexual orientation, partisanship, and/or class envy.

Ignorance is not just a problem on Election Day. Many individuals have only the dimmest awareness of important aspects of their locality, state, or nation. People know virtually nothing about important issues confronting their governing officials. Many can't even name their local, state, or national leaders. Finally, "dark areas of ignorance" aptly characterizes the public mind when it comes to foreign affairs.

What are the consequences of widespread political ignorance? Manipulation of ordinary people by what Angelo Codevilla calls the "ruling class," which includes political leaders, the news and entertainment media, and special interest groups. Instead of public opinion shaping public policy, most of the time Jane or John Q. Public has no political influence, because she/he knows little, if anything, about what is going on in the corridors of power.

Unless someone can find a way to stimulate greater grassroots political attentiveness -- the more interested people are in public affairs, the better informed they are -- expecting a substantially better-informed citizenry is wishful thinking. There are just too many spheres of life, such as family, friends, work, health, faith, recreation, entertainment, etc., that people believe are more pressing than public affairs. In the main, politics is a matter of tertiary concern.

Since almost all American adults rely on the mass media for the news, patterns of media dependence and styles of media coverage of politics also preclude the possibility of a much better informed public.

A Rasmussen poll in late February, 2013 found that 56% of "likely voters" said they got most of their news from either cable TV outlets (32%) or traditional network telecasts (24%). Another 25% claimed to rely most on the Internet for the news, 10% said print newspapers were their main news source, and 7% picked radio.

That mix of news sources helps understand the public's low levels of political knowledge, since electronic outlets (TV and radio) provide less information than print news. The internet's efficacy as a source of the news is less understood, although some claim the internet "makes us dumb" because it conveys information less effectively than traditional print outlets.

In addition, the substance and style of media coverage of public affairs has shifted in recent decades from "hard" to "soft" news. Hard news refers to media accounts of serious topics such as politics, business, or international events. These accounts are normally longer and convey more detailed information than soft news stories. Soft news stories typically focus on entertainment, the arts, and lifestyles, and tend to be aimed at tugging at the audience's heartstrings.

In summary, most people, most of the time, aren't very interested in public affairs, and consequently don't know a lot. Moreover, given patterns of media exposure and a larger amount of soft news, it's unlikely that things will change much.

What does it mean? At best, the U.S. will have bad political leaders, chosen by low information voters. At worst, American democracy will slowly shrivel due to widespread ignorance.

Ignorance seldom leads to happy endings.