STEELTON, PA. -- Mincing no words, the union leaders laid out the stakes for labor in Pennsylvania's special Senate election this November to 200 steelworkers gathered at their local's headquarters.

The local president called former attorney general Dick Thornburgh a "hack and chop artist" who cut essential state employees during his two terms as governor. "If you vote for him," declared the steelworkers' regional director, referring to the trade agreement pushed by the Bush administration, "your job will be on a fast track to Mexico."

"We've got to kick Dick Thornburgh's ass in 1991," said the head of the state AFL-CIO, "and George Bush's in 1992."

When the introductions were done, the men and women who work at the Bethlehem Steel plant on the banks of the Susquehanna River in this small town just south of Harrisburg were geared up to hear the would-be Democratic giant-killer taking on not just a former governor but a convenient embodiment of the Bush administration.

But when Sen. Harris Wofford took the microphone in Steelworkers Hall, the difficulty Democrats face here in winning a Pennsylvania Senate seat after 23 years of GOP control and using the race to point up Republican vulnerability on domestic economic issues became clear.

The hard edge that may well be essential for an underdog campaign became muted. Instead of the pounding inflection of an effective stump speech, Wofford's lines wandered, as if he was somewhat uncomfortable with the phrases he knows he must repeat.

"You need to say 'yes' when it counts," said Wofford. "Where was Dick Thornburgh when it was necessary to say 'yes' to a national health care plan. For three years he was head of the president's domestic policy council, and the other day he said, 'I am waiting for the secretary of health to come forward with a plan to see if I could support it.' How long Dick, how long? And where were you for those three years when you walked the corridors of power, and had the ears of the president, and did nothing."

Recalling Truman's "Give 'em hell, Harry" 1948 campaign, Wofford described a steelworker's enthusiastic call to "Give 'em hell, Harris" -- but the analogy seemed to die somewhere between the first and second rows.

Wofford, a virtual unknown in Pennsylvania, is an unlikely figure to be either serving as the banner-carrier for a Democratic Party claiming new vitality, or playing the role of David to Thornburgh's Goliath.

Appointed by Gov. Robert P. Casey (D) to fill the Senate vacancy created by the death of Sen. John Heinz (R), Wofford has never held elective office. Although the son of an entrepreneurial Tennessee insurance man, Wofford has the manner and style of a patrician New Englander deeply committed to civil rights, human rights and world peace.

At 65, Wofford's career is one of principled public service, from advising John F. Kennedy to call Coretta Scott King in the midst of the 1960 presidential campaign while her husband was in a Georgia jail, to serving as president of Bryn Mawr College. At the time of his appointment, he was Casey's secretary of labor and industry.

Now, with the guidance of such Democratic consultants as David Doak, Bob Shrum and James Carville, Wofford is struggling to shape a new, post-Reagan strategy not only for his own campaign, but for the Democratic Party generally. It is a strategy aimed at altering the image of the party from being primarily an advocate of programs and policies geared specifically to the poor to representing the broader interests of the working middle-class by emphasizing education, health care, tax cuts and trade policy.

"I am ready for the election to be a proving ground for a national Democratic message," Wofford said in an interview. "I want to put on trial the Bush domestic policy. I look forward to being the chief prosecutor."

In one of his first two television commercials, Wofford declares: "If criminals have the right to a lawyer, I think working Americans should have a right to a doctor."

In the other, he hits Thornburgh hard for the Bush administration's support for "fast-track" treatment of a proposed trade agreement with Mexico. The fast track would essentially force Congress to vote on any agreement on a take-it-or-leave-it basis, and has been strongly opposed by organized labor and many northeastern liberals.

"I've been fighting against the Mexican trade agreement because if that trade agreement passes, American plants and the jobs that go with them could be lost to Mexico where workers are paid $5 a day. My opponent, Dick Thornburgh, says we ought to put the Mexican trade agreement on a fast track. I disagree. I'm Harris Wofford, and I say: It's time to take care of our own."

The last line picks up on what Michael Donilon, Wofford's pollster, said was "the most common phrase" he has heard during the voter research he has conducted, replacing other frequently heard phrases, many with strong racial undertones such as "lots of people aren't working for what they are getting."

Although Thornburgh exudes confidence, there are signs he is worried about the potential impact of the kind of message Wofford is trying to use in a state that has gone through an industrial upheaval over the past 20 years. Thornburgh has, for example, pointedly broken with Bush on the issue of extending unemployment benefits, arguing that "in the final analysis, human needs should come first" despite President Bush's contention that there are not adequate funds to extend the benefits.

As for Wofford's charges of Republican economic royalism, Thornburgh counters that the middle-class who Wofford is seeking to help "is hurting, and they just had it socked right to them" by a state income tax hike from Casey, Wofford's political patron. Casey's favorability ratings, Thornburgh notes with relish, are in "free fall."

The former attorney general's media strategy to date is extraordinarily simple in comparison to Wofford's. The goal, in the words of his consultant, Greg Stevens, a partner of Roger Ailes, is "to put a couple of coats of varnish" on the generally favorable image Pennylvanians have of the former governor. In one of three ads, Thornburgh declares to the camera:

"Some folks have asked me why I'm running for the U.S. Senate. It's simple. I love this state. And, I think there is more we can do."

For Thornburgh, the stakes in this race are arguably greater than for his opponent. He arrived in Washington three years ago being mentioned as a presidential long shot in 1996. He left last month with his reputation somewhat diminished after a drug scandal involving a key aide, disputes over leaks to the press and, more recently, criticism for intervening on behalf of antiabortion demonstrators in Wichita, Kan., and allegations of ineffective investigation of the Bank of Credit and Commerce International scandal.

Thornburgh's aides say the criticism is an "inside-the-Beltway" issue, but that they are prepared for the assault everyone agrees is inevitable if Wofford is to have any kind of chance. But in the meantime, Wofford must struggle just to get known among voters in a race that will be over six weeks from today -- and he is now running far behind in polls.