With decision time fast approaching for those considering a run for the Democratic presidential nomination in 1988, here's a rundown of the field as it looks today, with the Gallup poll ratings: Gary Hart (53 percent). Former US senator from Colorado. With a paid staff of 30, Hart is tilling the ground in Iowa and New Hampshire, while taking off three days a week to pursue his law career. He is gradually paying off leftover debt (now at $1.6 million) from his 1984 campaign and trying to patch up relations with organized labor, with whom he fought when labor backed Walter Mondale in the last campaign.
Lee Iacocca (29 percent). Chrysler president. Not running.
Mario Cuomo (23 percent). Governor of New York. Could announce an exploratory committee within the next few weeks. Cuomo has shown impressive political savvy in New York and has expanded his appeal into Republican-voting suburbs. His major challenge: finding national themes that go beyond traditional liberal Democratic rhetoric and reach conservative voters, especially in the South.
Jesse Jackson (21 percent). Mr. Jackson got a strong response from a crowd of several hundred in farm-depressed Greenfield, Iowa, recently. But he must find a way to expand the colors in his Rainbow Coalition if he is to be considered a strong contender for the nomination.
Bill Bradley (11 percent). Senator from New Jersey. Not running, despite pleas from many moderates.
Charles Robb (6 percent). Former governor of Virginia. Insists he won't run - at least, not this time. Wants to get more foreign policy experience first.
Sam Nunn (5 percent). Senator from Georgia. Says he is leaning 60-40 against running but is under strong pressure from Southern friends, including Mr. Robb, to jump into the race. Just assumed chairmanship of Senate Armed Services Committee, a longtime ambition. Nunn might not be popular with liberal Democratic activists. One option: delay entry into the race until December 1987, then hope for a strong showing in New Hampshire and the South.
Dale Bumpers (4 percent). Senator from Arkansas. A Southern country lawyer who is pro-civil rights and more liberal than Nunn. He might do better than Nunn with blacks, antiwar groups, feminists, and other party activists. Has strong reputation as a ``giant killer'' in politics, with victories over Orville Faubus, Winthrop Rockefeller, and William Fulbright. Some doubt he has the overwhelming ambition sometimes considered a prerequisite to being president.
Michael Dukakis (3 percent). Governor of Massachusetts. So close to New Hampshire, ``the Duke'' could get off to a fast start in the primaries. But it's uncertain that he could expand his appeal into the South and West. Aides say he will decide whether to run by mid-March.
Joseph Biden Jr. (2 percent). Senator from Delaware. Insiders think Biden has a fairly good chance to win the nomination, despite scant name recognition. He's one of the Senate's two best Democratic speech-makers (the other is Bumpers), and appeals to the middle of the political spectrum. He will probably run.
Bruce Babbitt (1 percent). Former governor of Arizona. Babbitt is already off and running. His ideas are sometimes controversial. He once proposed, for example, that Washington take over all costs of health care and welfare, while states take over education. He has also proposed taxing social security benefits of high-income recipients.
Richard Gephardt (1 percent). Congressman from Missouri. Announces his presidential campaign next Monday in St. Louis. He could be a compromise choice between liberal Northern and conservative Southern factions of the party.
Paul Simon (no rating). Senator from Illinois. Strongly backs Bumpers for the presidency but may run if Bumpers opts out.
Bill Clinton (no rating). Governor of Arkansas. Probably would stay out of the race if Bumpers enters.