As we all know, it's been going on for more than a year now. In fact, there are those who claim it began the instant the last one ended. But to sticklers for form, the 1980 presidential campaign didn't officially get under way until last week, at precisely 12:01 a.m., Jan. 1.

So they're off and running. Make that re -running. The truth is, regardless of what this year's political strategists and image-makers would have us believe, nothing really new has occurred in the style of American presidential campaigning since 1844, when James K. Polk -- whose friends, incidentally, called him "Jimmy" -- ran and won the first "dark horse" race in history.

Nevertheless, for 18-year-old voters and those with short memories, it might be well to review the major genres of presidential campaign styles developed over the years. For as the late, great political observer Thucydides once put it, they are "likely, in accordance with human nature, to repeat themselves at some future time."

Here, then, is a quick-read form sheet on the political image strategies we can look for in the next 10 months. All that remains is for you, the better, to match the candidates to the images as the great race moves along, from the January starting gate to the October stretch drive:

The Magnificent Incumbent Campaign. This is the pet strategy of presidential candidates lucky enough to begin each campaign day with a view of the Washington Monument rather than a Holiday Inn parking lot. Though weighed down by the press of urgent public business, the Magnificent Incumbent somehow manages enough flotation to Rise Above Politics. The technigue dates back to the early days of the Republic, but was perfected by Abraham Lincoln in 1864, when his campaign adopted the then-novel slogan, "Don't Switch Horses in the Middle of the Stream." See also, Front Porch Campaign (William McKinley, 1900) and Rose Garden Special (Gerald Ford, 1976, and Jimmy Carter, 1980).

The Embattled Underdog Campaign. Popular with lightly regarded candidates, this particular style entered the mainstream of presidential politics in 1948, when Harry Truman, the candidate then residing in the White House, discovered that his Republican opponent, Thomas Dewey, considered himself so far ahead that he was running as the Magnificent Incumbent. This strategy is noted for the candidate's repeated utterance of the bromide, "The only poll I care about is the one taken on the first Tuesday after the first Monday in November." See also, Struggling Incumbent Campaign (Gerald Ford, 1976, and Jimmy Carter, pre-December, 1979.

The Front-Runner Campaign. At times, of course, an Embattled Underdog, given a hand by public sympathy, manages to slip his leash and move ahead in some poll before the one taken on Election Day, whereupon his advisers urge him to switch images and begin operating a Low Profile Campaign. This means that while as the Embattled Underdog the candidate didn't let an hour pass without challenging his chief opponent to debate "the real issues of this campaign," he now finds that the issues have indeed been aired, many times over. So that when his opponent (now the Embattled Underdog) begins issuing debate challenges, the Front-Runner sees no need "to waste valuable public time by rehashing stale arguments." See also, Bandwagon Campaign (Lyndon Johnson, 1964; Richard Nixon, 1968; and Ronald Reagan, 1980).

The Dark Horse Campaign. There are, however, campaign years when a particular political dog is so far under that he doesn't get an opportunity to become embattled. The strategic move then is to change animal imagery, from the canine to the equine. By so doing, the candidate hopes to appeal to the voters' latent fascination with the unfamiliar, or put another way, to their patent boredom with all the betterknown candidates who, by midsummer, are suffering from severe overexposure to Mike Wallace and Barbara Walters interviews. See also, Who's He? Campaign (James K. Polk, 1844; James E. Carter, 1976; George or John Whattsizname, 1980).

The Outsider Campaign. A favorite campaign style for candidates with military backgrounds, this technique in past years has resulted in the election of no fewer than four retired Army generals. In this gambit, the candidate, while in the act of vigorously seeking political office in Washington, takes every opportunity to deplore both politics and Washington. The style calls for frequent rhetorical reference to "that Washington crowd," "those federal bureaucrats," ad Potomacus. See also, Anti-Establishment Campaign (Army General Dwight Eisenhower, 1952; Navy Lieutenant Jimmy Carter, 1976; Space Cadet Jerry Brown, 1980.

The Reluctant Candidate Campaign. Finally, we come to the ultimate in campaigns disguised as noncampaigns, those conducted by presidential hopefuls who held themselves so aloof from the process that they run the risk of the public's becoming convinced they really don't want the job. Waiting for a Grassroots Draft to thrust them to the front of the pack, their preferred bromide whenever the subject of the presidency comes up is, "The office seeks the man." Indeed, it has -- once, in 192 years of presidential campaign history. The candidate was George Washington, the year 1788. Next time around, he ran as the Magnificent Incumbent.