FORT LAUDERDALE, FLA. -- Sen. Albert Gore Jr.'s high-risk strategy in this year's presidential campaign has been strikingly successful in winning the endorsements of southern Democratic leaders, but there are no clear signs yet that his message is taking hold among southern voters.

While his rivals are campaigning intensely in Iowa and New Hampshire, the Tennessee Democrat this week took a two-day trip through Georgia and Florida. The swing follows publication of two polls suggesting that Gore's "southern strategy" may not be working as well as once thought.

In the latest Atlanta Constitution survey of Super Tuesday states, published Sunday, Gore did not budge from a 13-percentage-point level of support between October 1987 and January 1988, running behind both Jesse L. Jackson and Gary Hart.

More importantly, Gore's southern base is heavily concentrated in his native Tennessee, where his support skyrockets to 64 percent, compared with only 5 and 8 percent in Florida and Texas respectively, the two largest states surveyed. Equally damaging, large percentages of white southern voters say they are going to vote in the Republican primary -- as much as 41 percent in Georgia.

Even some politicians sympathetic to Gore's desire to revive the moderate wing of the Democratic Party by concentrating on the South have privately asked why he isn't putting more time and money into the key primary contest in New Hampshire, where there are substantial numbers of conservative voters and where some prominent leaders have endorsed his candidacy.

Gore has dropped out of the Iowa caucuses, contending that liberal interest groups and an unusually liberal universe of caucus-goers distort the process there. These criticisms are not applicable to New Hampshire.

Gore defended his New Hampshire strategy on the grounds that Massachusetts Gov. Michael S. Dukakis "is a native son" and New Hampshire's "18 delegates compares with 1,400" on Super Tuesday. But while he may avoid the risk of trying hard and failing, Gore's New Hampshire strategy increases the danger that he might fail to make the starting lineup for the Super Tuesday competition, because those who do well in Iowa and New Hampshire will get so much media attention at a time when Gore is getting none.

Tennessee Gov. Ned Ray McWherter (D) looked at the latest poll figures and observed, "You've got to get in with those rednecks, wake 'em up, crank 'em up and get 'em going. The working people are the ones who elect people," he added, implicitly criticizing Gore's cooler approach.

"I suppose Al, like the other candidates, is locked into what you call 'the new politics' " of polls, television and carefully modulated messages, said John Seigenthaler, chairman, editor and publisher of the Nashville Tennessean, where Gore once worked as a young reporter. "The positions he takes on the campaign trail are calculated to present himself as a raging moderate."

Gore rejects the suggestion that he should be more aggressively populist. "I don't think the real answers to our problems involve dividing people into artificial categories," he said in an interview. " . . . {People realize} that you are not going to effect change by moving them relative to those who are better off."

A random check of voters at the courthouse in Hickman County, Tenn. -- the yellow-dog-voter heart of the Democratic South where white voters cast majorities for Walter F. Mondale in 1984 -- suggested ambivalence about Gore's message, despite his native-son status, among Tennesseans whose Democratic allegiance has roots in the New Deal coalition.

"I'm hung up on Gore," said Miriam Bogle. But despite her commitment, Bogle believes that the Democratic candidates need to reach "out more for the common folks, the workingman," in "speeches and everyday talk. Gore, maybe, is not . . . . We always saw the Republican Party as for the rich man. Now, maybe the Democrats are leaning that way too."

Malcolm Plunkett, 56, who works for the circuit court judge, thinks Gore is "capable of doing the job . . . . But he needs another four, eight years." The Democratic Party, he said, "in general represents the workingman, but it hasn't done a very good job of it . . . . We need a good man who is a moderate who has the people in mind, the poor people in mind."

"That is the dilemma of southern Democratic politics," said Merle Black, political scientist at the University of North Carolina. "You've got to campaign so you don't threaten the business-oriented Democratic leadership, but at the same time you've got to take stands that appeal to potential Democratic voters who are not part of that establishment."

As a fund-raiser, Gore has picked up the kind of Washington-based support that encourages a moderate message: the steering committee members for a recent Washington fund-raiser included premier lobbyists Thomas Hale Boggs Jr. and J.D. Williams, whose firms specialize in getting special tax breaks and other benefits for their corporate clients; Robert W. Barrie, chief lobbyist for General Electric; Ken Levine, lobbyist for Seagram and Sons; and Peter Kelly, whose lobbying firm represents Bethlehem Steel, Trans World Airlines and Johnson & Johnson.

Gore contends that he has "been more populist in action than anybody in this race," citing his work in behalf of legislation regulating chemical and toxic wastes, issues "that pit the average citizen against forces that are pretty powerful."

He stresses, however, that "throughout my political career I have tried to deliver a message that was not divisive, but promoted more understanding and cohesion. In the process, I have found myself getting a lot of support from independent voters including a very large number who might otherwise consider voting Republican."