The Rev. Jesse L. Jackson likes to divide the world between jelly-makers and tree-shakers, and count himself in the second group.

But later this week, at the halfway point between his first run for the presidency and a potential second run in 1988, Jackson will try his hand at some jelly-making: to wit, the creation of a permanent political organization.

Jackson will hold the "founding" convention of the National Rainbow Coalition at the Washington Convention Center Thursday through Saturday, an event expected to draw up to 1,500 of his supporters and to set in motion the chartering of scores of state and local Rainbow chapters.

The coalition will not function as a third party; rather, Jackson said, it will exist as a progressive force within the Democratic Party, pushing issues and endorsing candidates. "We plan to operate as enlightened Democrats, not anti-Democrats," said Frank Watkins, a longtime Jackson aide who serves as the group's interim executive director.

Jackson will not make a decision until early next year about seeking the Democratic presidential nomination, but he and his advisers stress that they consider the conditions ripe. The Democratic field figures to be crowded and bunched at the center and right-of-center of the party's ideological spectrum. Jackson, never one to hide his light under a bushel, will be a natural standout in such a group -- far more so since the party's leading liberal, Sen. Edward M. Kennedy (D-Mass.), took himself out of the race.

Moreover, the establishment of a "mega-Tuesday" of primaries on March 8, 1988, will serve up a block of delegates in Jackson's region of greatest strength, the South. He stands to be a beneficiary of that calendar consolidation, and some think he could arrive at the convention in 1988 with enough delegates to broker the choice of a nominee.

"Now don't you all go making me the front-runner," Jackson mock-scolded reporters at a breakfast meeting this week. "I'm the underdog!"

Some black elected officials in the South and elsewhere privately fret that a second Jackson presidential candidacy would serve no useful purpose. But there are far fewer skeptics toward him in the black community today than there were at a comparable point before 1984.

Jackson's strong showing in 1984, when he carried nearly 18.3 percent of the Democratic primary vote nationwide, has given him credibility. And he remains the most popular political figure of either race in the black community: a Washington Post poll in January gave him an 87-to-5 percent favorable-unfavorable rating among blacks.

Jackson has always resented being pigeonholed as the "black candidate," and in recent months he has been moving on a variety of fronts to broaden his base. He has:

*Met regularly with farm groups around the country, most recently last week in Chillicothe, Mo., where he addressed a rally of farmers protesting farm foreclosure policies.

*Reached out to progressive labor leaders. On Sunday he went to Austin, Minn., to meet with labor and management and offer his services as a mediator in the Hormel strike. This weekend, national leaders of three of the nation's largest progressive unions, the Communications Workers of America, the International Association of Machinists and the American Federation of Government Employees, are all expected to participate in the Rainbow Coalition convention.

*Met with independent oil producers in Houston, a meeting set up by Rep. Mickey Leland (D-Tex.), chairman of the Congressional Black Caucus. Jackson told reporters this week he believes the price of oil should be jawboned up. "More than J.R. Ewing is affected by $10-a-barrel oil. You have thousands of energy workers losing their jobs . . . and you get right back into having a dependence on foreign oil. Gas is cheaper, but is freedom worth a quarter? I say it is."

*Waged a nationwide antidrug campaign in high schools, where his modus operandi is to challenge students to publicly confess their drug abuse and pledge to kick the habit. Some question the effectiveness of his methods, but few doubt that by leading a crusade against drugs grounded on a moral appeal, Jackson has latched on to a potentially potent political issue.

*Led a boycott against the CBS-TV affiliate in Chicago, WBBM-TV, that began after the station removed a black from his job as coanchor of the local news. That effort was orchestrated by Operation PUSH, Jackson's Chicago-based economic self-help organization.

PUSH remains in existence, but the National Rainbow, with a political orientation and a staff of 11 headquartered here in Washington, is more and more becoming the vehicle for Jackson's tree-shaking. And his jelly-making.