Like the rest of us, candidates for president have to make a living. But in recent American history, the most successful candidates have usually been unemployed - at least in a political sense. That means they do not hold a current political office and do not have to worry about shirking their day-to-day responsibilities to run for president.

In fact, most presidential scholars have noted for some time that it is almost required that a candidate for president be unemployed to be able to spend the time necessary to be both nominated and elected. Campaigning for the highest office in the land is stressful and time consuming, invariably involving both early mornings and late nights. Often, candidates end the campaign with sore throats and hoarse voices, indicating the burden placed upon their health.As recently as 1984 when only the Democrats had to scramble for the nomination while the Republicans waited to oppose with their incumbent president, it was clear that the unemployed candidate had the advantage. Sitting senators such as Alan Cranston, Ernest Hollings, John Glenn and Gary Hart all worked as hard as they could, but had difficulty competing against the unemployed Walter Mondale, who became the party's nominee.

In 1980, two unemployed Republicans, George Bush and Ronald Reagan, battled each other for the right to oppose the incumbent president, Jimmy Carter. Senator Howard Baker complained that year that it was virtually impossible to run for president when he had to keep returning to Washington for an important Senate vote or meeting. In 1976, the virtually unknown former governor of Georgia, Jimmy Carter, left all the other Democrats behind in great part because of his ability to spend all his time campaigning. Morris Udall, still serving as a member of Congress, managed to come in number two in several primaries, but never number one.

In 1968, the unemployed Richard Nixon emerged victorious in spite of the early lead of sitting Republican Governor George Romney of Michigan. Governor Nelson Rockefeller of New York also competed that year, but unsuccessfully. Nixon had been extracting IOUs across the country for four years while his potential opponents were busy governing.

It would seem, then, that the 1988 presidential campaign has produced a phenomenon. In the absence of a president seeking re-election, both parties have been struggling through the primaries and caucuses, and both have settled on fully employed nominees. George Bush, the Republican nominee, is the vice president of the United States and Michael Dukakis, the Democratic nominee, is the governor of Massachusetts.

Moreover, both parties included fully employed competitors who eliminated the unemployed candidates, with the exception of Jesse Jackson, who stayed in almost as long as the Duke. Bush had to contend with Senator Robert Dole and Representative Jack Kemp, both of whom performed far better than the unemployed Peter DuPont, Al Haig and Pat Robertson. On the Democratic side, Dukakis battled Representative Richard Gephardt, Senator Paul Simon and Senator Al Gore, all of whom did better than the unemployed Bruce Babbitt and Gary Hart.

In spite of local efforts in Massachusetts by the Republicans to prove that the state has suffered because of an absentee governor, it has seemed an advantage this year to be a fully employed candidate. It suggests that a person who is in touch with current problems and who has the most recent hands-on experience must have enormous energy if he can both govern AND run for president.

Dukakis in particular has set the tone by campaigning for three days and governing for one, then getting back on the plane fully energized. One of the reasons that Governor Mario Cuomo of New York did not run this year was the alleged impossibility of governing at the same time. The Duke has proved that contention to be wrong. Moreover, he has pledged to stay in office as governor until the general election. He has astonished reporters with his energy and his continuing attention to state problems when he returns to Massachusetts - and without a hoarse voice or sore throat. Undoubtedly, those politicians such as Howard Baker and Gary Hart who purposely decided not to seek re-election so that they could run for president after they stepped down from the Senate have taken note. The future trend is definitely toward fully employed presidential candidates.