MANCHESTER, N.H. — There was no topic too extraneous or narrow for Newt Gingrich on Monday as he made his case to employees of a public utility company in New Hampshire.

“We’re having a revolution in biology. We’re having extraordinary breakthroughs.”

“We have in Arizona naturally occurring dust storms, because we’re a desert.”

“We want the most modern equipment in the world, so American workers are the most productive in the world, so we can compete head to head with China and India.”

Gingrich broached these and other issues in a room crammed with New Hampshirites, who will head to the polls Tuesday for the first-in-the-nation primary. They stood, they sat on the ground, they flowed over into the hallways. And after he finished speaking, Gingrich gave each a chance to shake his hand and snap a photograph.

But as Gingrich entered the hall at Public Service of New Hampshire, a regulated energy company, there was complete silence. Unlike most campaign events, where the candidate’s arrival is greeted with commotion on all sides, the only sound in the room was the click of a photographer’s camera as Gingrich slowly made his way to the podium.

“I am the only candidate on our side who has actually effected national change,
" said the former House Speaker, though acknowledging that Sen. Rick Santorum (R-Pa.) had played at least a limited role in national policy.

While most of his rivals have based their closing arguments to New Hampshire voters on more emotional, principles-based appeals, Gingrich waded deep into the intricacies of regulatory policy and economic history — and his role in it.

He recalled helping develop supply-side economics decades ago, recounting his work with President Reagan to promote conservative principles and detailing the executive orders he would issue on his first day to dismantle President Obama’s industry rules.

And as he spoke — for almost an hour — at his side stood his wife, Callista, hands clasped in front of her emerald green suit as she watched her husband with an immutable smile. She said not a word during the entire event.

“It’s not just a game,” Gingrich said of the choice voters would be making in less than 24 hours. “It’s a fundamental process of free people trying to think through their future, for our children and our grandchildren.”