It is the paradox of political journalism: The most important aspect of a presidential campaign—how flesh-and-blood voters make up their minds—is the least covered and understood.

Sure, reporters devoutly worship at the altar of polls and study their gyrations with an intensity unmatched since the ancient Greeks struggled to decipher the prophecies of the Oracle at Delphi. But media explanations for fluctuations in the survey numbers (the Bain attacks catching fire, worries about the direction of the economy) are mostly guesses. The closest contemporary analogy is to stock-market reporters who glibly attribute the daily decisions of millions of investors to a single factor like dwindling confidence in the euro.

The best way for a reporter to understand the internal deliberations of undecided voters (warning: shocking revelation ahead) is to ask them in person. At minimum, this exercise will remind you that most voters are a lot smarter about choosing a president than is commonly assumed at Manhattan parties. Bulletin: The American booboisie died with H.L. Mencken.

Voter interviews also remain the best way to double-check the polls and pick up trends that may not have yet have registered in the surveys. Maybe five days before the 2012 South Carolina primary, when the polls still showed Mitt Romney with a comfortable lead, Washington Post reporter Karen Tumulty and I had drinks after a day of independently interviewing GOP voters. Both of us tentatively noted that we were picking up a surprising amount of pro-Gingrich sentiment. Gingrich went on to win the primary by a double-digit margin.

And probably the best way to determine whether attack ads are working is to see whether you pick up the themes of these TV spots in unstructured voter conversations. If you watch the ads and then chat with voters, you can often hear the echoes of the media consultants.

Yet I sense—based on an impressions, rather than hard data—that the tradition of chatting with voters in cafes over breakfast or in Greek diners during the lunchtime rush is becoming as outmoded as candidate press conferences.

There are exceptions, like this recent Los Angeles Times article by Michael Finnegan charting the mood of a middle-class Cleveland suburb. Or this Associated Press story by Charles Babington about undecided voters in Virginia.

But, for the most part, voters remain the forgotten men and women of American politics. The imperatives of the modern media business don’t help here. Serious conversations with voters are a labor-intensive exercise, since the goal is to draw them out and let them ramble. But a quick rewrite of a new Colorado poll is apt to get more online clicks than two days of reporting from Pueblo. And it is hard to get many retweets when you type: “Retired Richmond electrician Fred Smedley troubled by Mitt’s ‘lack of compassion,’ but still won’t commit to ‘weak leader’ Obama.”

Still, the more campaigns I cover, the more I find voters to be far more interesting than campaign operatives and their self-serving spin, or candidates who fear spontaneity more than defeat. In 2004, for example, a 30-year-old unmarried nurse in Des Moines told me that she loved John Kerry’s health-care plan but was voting for George W. Bush. Her reason: “You don’t change presidents in the middle of a war.” Eight years later, that interview still provides a frame for understanding Kerry’s defeat. And Bush, by the way, carried Iowa that year by just 10,000 votes.

The best voter interview of my career came in Ohio, the ultimate swing state, during the 2010 gubernatorial race between Democratic incumbent Ted Strickland and Republican John Kasich. I was in Bellefontaine chatting with Dave Zellers, a county health official, who asked me where I was staying that night. I vaguely mentioned stopping at one of the interchangeable chain motels that I had passed coming off the interstate. “No,” Zellers said with surprising passion in his voice, “you absolutely have to stay at the Comfort Inn.” Why? Are you an owner? “We are in the bed bug capital of America,” he explained. “And the Comfort Inn just passed inspection with flying colors.”

That nugget of consumer advice, by itself, would have made my campaign week. But then Zellers explained why he was switching from Strickland to Kasich. “Personally, I like Strickland,” he said. “He’s a good guy. But you can’t lose 400,000 or 500,000 jobs without paying a price.” I have thought about that paying-a-price comment regularly as I have wondered whether Obama can survive a national unemployment rate of more than 8 percent. Especially since, thanks to people like Zellers, Strickland lost his reelection bid by 75,000 votes.

Walter Shapiro just chronicled his ninth presidential campaign. He writes the “Character Sketch” political column for Yahoo News. Follow him on Twitter @WalterShapiroPD.