DES MOINES, Iowa -- The novelist Nelson Algren has been long credited with handing down three memorable rules of life: "Never play cards with a man called Doc. Never eat at a place called Mom's. Never sleep with a woman whose troubles are worse than your own." Algren, in truth, may have been the popularizer rather than the creator (see Ralph Keyes' fascinating 1992 guide to misattributed quotes: "Nice Guys Finish Seventh"). But still it remains hard to top these eternal verities.

Operating in less exalted realms, "Roadies" has long been guided by another set of rules of the road. Like Algren's three-part list, the Roadies' compendium of political folk wisdom can be boiled down to three succinct sentences. While there is no ironclad guarantee that these dictums always work -- and they will be tested in the weeks ahead as never before -- the Roadies Rules historically have boasted an enviable track record for accuracy.

No New York mayor, since the modern city was created in 1898, has ever been elected to another political office.

This one first came into play back in 1972 when Republican-turned-Democrat John Lindsay ran (badly) for president, and the rule proved its staying power in 1982 when Ed Koch lost a gubernatorial primary to Mario Cuomo. A few months ago, Rudy Giuliani seemed to many (but not to Roadies) to be the ex-mayor likely to burst the curse when he was riding high in the polls. But now that "America's Mayor" has all but conceded Iowa and New Hampshire -- and three marriages plus Bernie Kerik are taking their toll on his national poll numbers -- there is a growing sense in the John McCain, Mitt Romney and Mike Huckabee camps that, yes, you can fight City Hall.

Always bet against the youth vote making a difference.

Ever since the 26th Amendment gave 18-year-olds the right to vote in 1971, apostles of the young have been promising a youth-quake in the next election. We are still waiting. Rock the Vote, which has been around since 1992, is getting middle-aged. For all the yowzas over YouTube and the fandangos over Facebook, Iowa (where a younger caucus-goer can be defined as a voter under 50) seems an unlikely setting to defy this enduring rule. Kathy Frankovic, the survey director at CBS, recently pointed to historically low participation rates among the young voters in Iowa to explain why polltakers do not have a cellphone problem in reaching a random sample. As a result, Roadies is tentatively guessing that Hillary Clinton will do better in attracting older first-time caucus participants (say, a 59-year-old waitress smitten with the idea of a woman president) than Barack Obama will do in motivating college students still on Christmas break to caucus in their hometowns.

Insurgents may win news-magazine covers, but they lose the nomination to establishment candidates in the end.

It is easy to understand the media hoopla over Mike Huckabee (and to a lesser extent, John Edwards). Bored with Rudy and Romney, Hillary and Obama, the press pack needed a new story line -- and Huckabee obliged by vaulting to the top of the Iowa polls. But not since Jimmy Carter in 1976 has a true political outsider raised his hands in triumph at his party's convention, although many have won Iowa or New Hampshire. The lionized long-shot losers include Gary Hart (1984), Pat Buchanan (1996), Bill Bradley and John McCain (2000) and, of course, Howard Dean (2004). Although political reporters -- who crave upsets as much as any sports fan -- are loath to admit it, we are often akin to midway barkers who loudly insist that the games of chances are not rigged and anyone can win a kewpie doll.

Sure, these Roadies' Rules run the risk of being upended between now and the Feb. 5 Super Dooper Party Pooper primaries in 23 states. But as I drive around Iowa during this closing week before the climactic caucuses, I intend to stick with the immortal truths of Nelson Algren. So no matter how hungry and weary I am, no matter how beguiling the small-town restaurant looks, I will never eat at a place called Mom's.