JACKSON, MISS., FEB. 29 -- Sen. Robert J. Dole (R-Kan.) has decided he can be the toughest guy on the presidential campaign block.

Tough has become one of his favorite words and his own toughness a central theme as he campaigns against Vice President Bush across the South, a region where all of the presidential candidates are trying to project a manly, even macho, image. In one 30-second segment of a speech to the Georgia House of Representatives in Atlanta today, Dole used "tough" six times.

"I believe I have a certain quality that some may be lacking," he said. "I am tough. I understand you have to be tough to make tough choices. You have to be tough to deal with the Congress . . . .

"You have to be tough to provide moral leadership in America. You have to be tough to provide the political leadership in America."

Variations of this theme have been part of the Dole campaign from the start. It is one way that Dole has attempted to contrast himself with Bush, who he implicitly suggests has led too privileged and pampered a life to deal with the country's problems.

But in recent days, this toughness theme has led Dole to make increasingly strong statements on foreign and trade policy as he seeks to appeal to conservative Republicans who hold the key to the March 8 "Super Tuesday" contests in 14 southern and border states.

Like the other candidates, Dole has found Panama's military strongman, Gen. Manuel Antonio Noriega, a convenient target. He has suggested the use of U.S. military force to protect American interests in Panama, called for a trade embargo of Panama if Noriega does not leave the country in 30 days and said the Organization of American States should meet to "derecognize that puppet government."

Today, he went a step further, suggesting that the United States consider backing out of the Panama Canal treaties, which turn over control of the canal to Panama by the end of the century and which were ratified by the Senate during the Carter administration.

Asked how the United States could avoid turning over the canal, Dole said he would have to reread the treaties. "There may be a clause," he said. Dole said his vote against ratification of the treaties "looks better and better every day."

Dole has used similarly strong rhetoric in recent days on trade policy, particularly in South Carolina, where the textile industry has been damaged by foreign competition. In Greenville, S.C., he described the United States as "a dumping ground" for foreign goods.

"We've got to have more than plans, more than promises from the Japanese, more than promises from the Europeans," he said. "What we need is a little muscle. We need someone to stand up and say we've had enough."

Dole denied today that he has adopted protectionist trade rhetoric to appeal to resentful voters in economically hard-pressed regions of the South. He said he opposed quotas and tariffs and was calling for "a more aggressive trade policy." But Dole has consistently left the outlines of such a policy vague.

"I'm not so interested in pleasing the State Department, as Vice President Bush is, or pleasing a few diplomats around the world," he said today when questioned about trade policy. "I want to protect jobs in Georgia and North Carolina and Alabama and South Carolina, in the textile mills and on the farm."

Dole said his toughness theme was an attempt "to break this veneer that somehow {Bush} is cloaked with leadership. It's not the jobs you've held, it's what you've done with the jobs you've had. And have you left any footprints anywhere?"

Contrasting his record in the Senate with Bush's role during the Reagan administration, Dole said, "He can't cite one thing in the last seven years that he's done."

As Super Tuesday approaches, Dole is attempting to blend the toughness theme with two others. One is a revival of his "one of us" slogan, an attempt to contrast his humble origins and personal and political struggles with Bush's background.

"I got here just like you did," Dole told the Georgia legislators. "I got here the old-fashioned way. I earned it. Nobody gave it to me. Nobody handed it to me."

But Dole also stresses a theme of compassion that may play a greater role in his pronouncements since Bush, at a GOP debate in Atlanta Sunday, suggested that mental illness is a major cause of homelessness in the nation. Citing the homeless and hungry, Dole pledged today, "We're not going to turn our back on the left-out and the down-and-out in a Dole administration."