TRENTON - U.S. Sen. Frank R. Lautenberg insists his decisive victory in Tuesday's Democratic primary over a challenger 34 years younger laid to rest any questions about his age.

But come the general election, it may be the age of Republican presidential candidate John McCain that helps Lautenberg - the third-oldest member of the Senate - get past the issue.

Lautenberg, 84, said the question on voters' minds was effectiveness, not age, arguing that he will be a more effective advocate than Republican opponent Dick Zimmer if New Jerseyans return him to Washington for a fifth term.

"People don't give a darn about my age. They know I'm vigorous. They know I've got plenty of energy," Lautenberg said Tuesday night after defeating U.S. Rep. Robert E. Andrews of Haddon Heights, 59 percent to 25 percent. Andrews, 50, had made age a major issue in the primary campaign.

Zimmer, a former U.S. representative who is 63, has pledged not to make age an issue in the November election.

Some say the fact that Zimmer will campaign in New Jersey alongside McCain, the presumptive Republican presidential nominee, who at 72 could be the oldest person elected president, blunts the age attack.

McCain's presumptive Democratic challenger, Illinois Sen. Barack Obama, is 46.

"The dominant feature in this election is going to be party," said Ingrid Reed, director of the New Jersey Project at Rutgers University's Eagleton Institute of Politics.

Like McCain, Lautenberg has been dogged by the age issue. If elected, Lautenberg would be just shy of 91 when the six-year term ends.

In the Senate, only two members are older: Democrat Robert Byrd of West Virginia, 90, and Republican Ted Stevens of Alaska, who is two months older than Lautenberg. Former South Carolina Sen. Strom Thurmond served until he was 100.

"I don't tire because I enjoy life and I enjoy being of service to the people of the country and our state," Lautenberg said. "I'm invigorated by the work, and I'm not at all tired."

So invigorated that he won't guarantee that the next term would be his last.

"This job isn't term-limited," Lautenberg said.

Jim Dau, a spokesman for the AARP in Washington, said it was a myth that age mattered.

"Age is less of an issue and more of a distraction," he said. "In the end, age is an arbitrary number."

Dau said older voters were far more concerned about pocketbook issues such as health care, housing costs and national security than about age.

"Those are the issues that are driving their choices," he said.

New Jersey voters may see things differently.

Of those asked in a Rutgers-Eagleton poll in August, more than 60 percent said Lautenberg's age would make it difficult for him to represent New Jersey effectively in Washington.

In a Quinnipiac University poll released in July, 54 percent of 1,604 Garden State voters said Lautenberg was too old to run again, while 40 percent disagreed.

"The people who did surveys on this all felt the less engaged voters were more likely to say, 'Who is this old guy?' than the faithful Democratic voters," Reed said.

Making age an issue is something that Lautenberg himself has done to get elected. In his 1982 Senate campaign against U.S. Rep. Millicent Fenwick, who was 72, Lautenberg questioned her fitness for the seat.

For his part, McCain has developed a ready response to the age question.

"I have a few years on my opponent," he said the other day, "and I'm surprised such a young man has bought into so many failed ideas."