YPSILANTI, Mich. — Mitt Romney and Senator McCain talked jobs and Michael Huckabee spotlighted his opposition to abortion yesterday as the Republican presidential contenders sought to make their most effective pitch for votes before Michigan’s potentially make-or-break primary.

Mr. Romney, seeking a rebound in Tuesday’s primary after losing to Mr. Huckabee in the Iowa caucuses and Mr. McCain in the New Hampshire primary, made an impromptu stop at a General Motors plant near here after 200 layoffs were announced last week.

He pledged to make restoring the domestic auto industry — once the linchpin of Michigan’s economy — a top priority if elected president.

“It is simply wrong for Washington to be aware of what’s going on in Michigan without doing something about it,” Mr. Romney said earlier in snow-covered Traverse City. “And they need to recognize that they just can’t write Michigan off and say, ‘Oh, it’s too bad Michigan’s having such a hard time,’ because in some respects, Michigan is like the canary in the mind shaft: What Michigan is experiencing, the whole nation will experience unless we fix what’s happening in Michigan and learn lessons here we can apply across the nation.”

Mr. Romney’s criticism of Washington was a none-too-subtle shot at Mr. McCain, who has said that some of Michigan’s lost jobs are gone forever. He defended his comment during a raucous rally before 400 supporters in Warren.

“I had to give some straight talk,” Mr. McCain said. “Jobs are leaving the state of Michigan. They have left and will not come back, but we’re going to create jobs, we’re going to create a new economy. This is the smartest technological place in America. We have the smartest people here. We can do it. We can create jobs here.”

Both he and Mr. Romney called for cutting taxes and government help in investing in technology.

“Detroit once saved the world, Michigan once saved the world in World War II, and they can do it again,” Mr. McCain declared.

As he spoke about the economy, the crowd broke out several times in applause and spontaneous chants of “Mac is back.”

Economics were a focal point because Michigan’s unemployment rate, at 7.4% in November, is the highest in the country by a full percentage point. It also is about 50% higher than the national average.

Bureau of Labor Statistics figures show the state shed more than 76,000 jobs in the 12 months ending in November, a period in which the national economy added 1.5 million jobs.

Mr. Huckabee’s alternate focus on social issues highlighted his effort to reinvigorate the coalition of religious voters that propelled him to victory in Iowa.

The former Southern Baptist minister emphasized his opposition to abortion as he urged about 100 pastors in Grand Rapids to support him and use their address books and e-mail lists to mobilize others.

“I don’t presume that you will support me because of a common faith,” Mr. Huckabee told them. “I know that I have to earn that. But I also recognize this is a unique opportunity. For a long time, those of us who are people of faith have been asked to support a candidate who would talk to us. But rarely has there been one who comes from us.”

He added, “Life is in the balance.”

Comparing abortion to slavery, Mr. Huckabee also said that overturning the Roe v. Wade decision legalizing abortion would merely allow states to decide whether to value one life or another and called for a constitutional amendment banning the practice. He also played up his opposition to gay marriage, saying that traditional marriage helps “train our replacements.”

While only 34 delegates were up for grabs in Michigan Tuesday, the candidate activity highlighted the state’s importance in the battle for momentum.

Mr. McCain, a senator from Arizona, is hoping to build on his New Hampshire victory. Mr. Huckabee, the former governor of Arkansas, is trying to recapture energy heading into next week’s South Carolina primary. He decamped from Michigan to attend church Sunday in South Carolina, but he changed his schedule to return to Michigan Sunday afternoon and remain until Tuesday amid heightened expectations of a strong finish.

Mr. Romney, meanwhile, is seeking a first-place finish after his earlier second-place finishes prompted questions about whether he has hit a ceiling of support.

Mayor Giuliani, who was campaigning in Florida yesterday, has ceded Michigan to the others. A former Tennessee senator, Fred Thompson, was campaigning in South Carolina.

Mr. Romney, a former Massachusetts governor who grew up in Michigan and whose father, George, was a three-term governor of Michigan in the 1960s, was accompanied by his wife, Ann. She poured on the local charm by recalling growing up in the state and vacationing summers on Lake Michigan.

“I don’t think there is a more beautiful place than right up here. It is so beautiful,” she said. “Michigan is our home and we love it.”