With New England on his schedule but the Mideast on his mind, a subdued Sen. Edward M. Kennedy (D-Mass.) went through the paces of presidential campaigning today but muffled his verbal punches at President Carter.

What should have been a banner campaign day in Kennedy's home country -- the day included friendly crowds, a tough, specific speech on energy, and a rich vein of "photo opportunities" -- turned into a blah parade of appearances by a candidate who was clearly unwilling to take sharp issue with the president.

The problem was the confusing and somber news that filtered in all day from Iran and Pakistan. In a time of crisis, Kennedy was in no mood to challenge the White House on anything.

Instead, at every stop as he stumped through New Hampshire and eastern Massachusetts, the senator went out of his way to make it clear he stands with Carter on the Mideast situation.

"Let me say how important it is," Kennedy said in Milford, N.H., abruptly interrupting his prepared speech to make the point, "for the country to be speaking with a single voice . . . about the situation in Iran and the Americans whose lives are threatened in Pakistan."

In Manchester, where Kennedy read through his prepared speech in distracted tones, he came to life only in an ad-lib paragraph reiterating his support for Carter.

"As a united people, we support our government . . . We will not stand by when our citizens are threatened . . . We will not submit to blackmail . . . On this issue at this hour, we remain one nation indivisible."

Until the news from the Mideast came in, the conditions were in place for a day of all-out anti-Carter campaigning on Kennedy's part.

In Nashua, N.H., Kennedy stood on a sunny, wind-swept bluff 35 feet above Jackson Falls and talked about the need for energy sources like water, wind and solar power.

But the other shoe -- Kennedy's regular complaint that Carter has fumbled opportunities to develop such sources -- was not dropped today.

In Milford, Kennedy walked into a full-scale political pep rally in a high school gym.

The student audience was so enthusiastic that they cheered not only for the local politicians flocking around him -- even the superintendent of schools. (They did boo their own school principal, however.)

The school band, unable to locate sheet music for the Democratic Party anthem "Happy Days Are Here Again" played the closest thing it could find -- the theme from "Happy Days."

But Kennedy did not respond. He read his speech quietly, including the attacks on the oil companies, which he usually delivers with great elan.

The major address of the day, and one of the major addresses of his campaign to date -- the energy speech in Manchester -- was delivered in the same fashion.

In that talk, Kennedy offered his most detailed explanation yet for one of the most controversial policy positions he has enunciated his call for retaining control on oil and gas prices.

As he has before, Kennedy said decontrol is "an economic disaster."

"It will cost the average family $1,000 a year. It is a regressive plan that imposes the heaviest burdens on those who can least afford them . . . Perhaps decontrol will drive them into living in a permanent chill -- and pay more for the privilege of getting sick."

(The Associated Press reported that a Department of Energy spokesman called the $1,000 figure "erroneous," saying next year's impact is expected to be about $100. Kennedy aides said the figure represents the money the oil industry will realize from decontrol divided by the number of families in the country and adjusted to cover cost increases of nonenergy items.)

And Kennedy rejected the suggestion, set forth by Carter when he ordered price decontrol, that higher oil prices effectively spur conservation by consumers and exploration by oil producers.

Kennedy said the conversation benefits of decontrol will be "marginal." And he rediculed the notion that decontrol is needed to spur new discoveries.

"If the industry will not respond when average profits climb 105 percent," Kennedy said, "what profit increases will they next demand -- 300 percent?"

The speech also complained of Carter's "incompetence" in building a strategic oil reserve.

"The Energy Department has poured 92 million barrels into salt domes for storage," Kennedy said, his quiet tone belying the tough language. "But they forgot to put the equipment in place to pump the oil back out . . . we still lack the capacity to ride out an embargo on foreign oil."

At the end of the day Kennedy went to his home on Cape Cod to spend the holiday weekend with his family.His wife, Joan, who has lived apart from him for two years, will be with him over the weekend.