LORDSTOWN, Ohio -- On a day when world oil prices gushed to yet another record and General Motors stock dropped to a three-decade low, Arizona Sen. John McCain toured the sprawling General Motors plant here yesterday touting his plans for diversifying the nation's energy resources.

At the same time, his presidential campaign launched a new national TV effort to promote the Lexington Project, as he has dubbed the litany of ideas he has advanced to boost alternative energy sources and curb the nation's dependence on foreign oil.

"This issue is a nexus of national challenges," the Republican said. Energy translates to national security, he said, in an environment where "we are dependent on countries who don't like us very much for our energy supplies. ... Some of that money ends up in the hands of terrorist organizations. It's a fact; it's just a fact."

Mr. McCain dismissed Democratic criticism of one aspect of his plan -- that a promised $300 million award for new battery technology is a "gimmick." He noted that Charles Lindbergh's historic New York-to-Paris flight had been spurred by a similar cash prize.

The Arizona senator maintained his support for a summer gas-tax holiday, another proposal that critics have also called a gimmick. He defended it as an aid to lower-income drivers in particular, but characterized the core of his energy plan as a long-term blueprint.

He said energy issues had been ignored for too long, and that it was going to be difficult to address them. "It's going to be long; it's going to be hard, and it's going to be tough."

Mr. McCain repeated his goal of seeing 45 new nuclear plants across the country, while promising billions in subsidies to develop clean-coal technology. He noted that the output of both new coal- and atomic-fired plants will be needed if companies such as GM move toward vehicles that rely on electricity rather than oil.

During the state's Democratic primary, both candidates tried to exploit dissatisfaction with the North American Free Trade Agreement and other trade accords. In answer to a question at a brief town hall session with plant employees yesterday, Mr. McCain reiterated his commitment to free trade, but said he was open to reviewing such treaties' enforcement mechanisms.

On the eve of a Latin American trip that will include Colombia, he called again for the ratification of a free-trade accord with that nation -- one, he said, that had offered crucial help to the United States in the war on drugs. Congressional Democrats have blocked the treaty, in part because of allegations that the Bogota government has repressed labor union members.

At a subsequent news conference, Mr. McCain rejected the idea of "a classic bailout" for U.S. auto firms struggling with the effects of high fuel prices and stiff foreign competition. He said, however, that he would promote federal assistance to help pay for costs of research into new technologies.

"I think it depends on what you mean by bailout," he said in answer to a question. "If you're talking about it in classic terms, I'm afraid not, ... [but] I would seek pure research-and-development backup by the government."

The presumptive Democratic presidential nominee, Illinois Sen. Barack Obama, has said he would be back in Ohio many times between now and the November election, noting that no president since John F. Kennedy had reached the White House without winning the state. President Bush won the state narrowly in 2004. Early trial heats for the November election have produced conflicting results.

In its most recent poll, Rasmussen Reports found a virtual tie last week, with Mr. McCain at 44 percent and Mr. Obama at 43 percent in a state in which he was soundly defeated in the Democratic primary. A Quinnipiac survey earlier in the month found a modest lead for the Democrat, with 48 percent for Mr. Obama and 42 percent for Mr. McCain.

In a conference call with reporters Thursday, Gov. Ted Strickland contended that Mr. McCain's promised return visits to Ohio would be in vain. According to a transcript of the call, he said the Republican would not be able to achieve "any significant foothold" in the key state, questioning his appeal in an area of the state that has suffered decades of job losses in manufacturing industries.

"I cannot imagine that Senator McCain could hope to gain political advantage in the Mahoning Valley. It's an area that has been devastated by Bush administration policies." Mr. Strickland said.

After a brief auto plant tour, Mr. McCain took questions from about 100 employees seated in front of a large American flag. He wore a blue blazer and open-collar light blue shirt. At one point, he apologized to the crowd for the effects of a cold, but when reporters later asked about his malady, he replied with seeming impatience, dismissing it as insignificant.

But Mr. McCain acknowledged the ills of the nation's economy. "American is hurting now; the heartland of America is hurting," he said.

The plant he toured offered a relatively bright contrast to the job cuts of the Mahoning Valley and the battered stock price of GM. Lordstown was spared from a recent wave of plant closings by the troubled auto giant. The facility, which manufactures the Chevy Cobalt, is poised to add a third shift, an expansion that translates to 1,400 new jobs.