DARTMOUTH, Mass. — Sen. John F. Kerry took himself out of the race for president four months ago when he announced, on the floor of Senate, that he wouldn’t be making a second bid for the White House.

But, to hear him talk yesterday, you couldn’t chalk up his decision to a sense of defeat or indifference.

In the keynote address at the 107th commencement at the University of MassachusettsDartmouth, Kerry urged the graduates to become politically involved.

“I’ve been in public life now for almost every day since I left college. And I’ve seen a lot of things that were good, a lot of things we’ve changed.

“But I’ve also seen a level of procrastination, a level of avoidance, a level of irresponsibility, and a level of danger growing that challenges all of us. And what I know after all those years is it doesn’t have to be this way,” he said.

The speech was sprinkled with pop references. Although no longer a member of the younger generation, Kerry, 63, included Jay Leno-worthy quips about Paris Hilton, Paula Abdul, Lindsay Lohan and Britney Spears.

He even threw in remark about Sanjaya Malakar, the 17-year-old American Idol contestant whose voice was so bad his candidacy was promoted by the people, such as radio host Howard Stern, trying to topple the popular Fox TV program.

“I received over 59 million votes for president, yet I am humbled to know that it’s still 5 million fewer people than voted for Sanjaya,” Kerry said.

In terms of being “with it,” the junior senator from Massachusetts was almost upstaged by senior class president Kristi Nicole Matsumoto.

Matsumoto, who was graduating with a bachelor of fine arts in visual design, had a friend plug her iPod into the sound system. For the next few minutes, a podcast rang out through the Vietnam Veterans Peace Memorial Amphitheater, with the voices of Matsumoto’s classmates recounting their experience as undergraduates.

In the four years since they enrolled, Matsumoto said, she and her classmates have seen the Dartmouth campus change from “a predominantely commuter school to a residential institution.”

Nearly 45 percent of the 8,800 students at the University of Massachusetts Dartmouth live on campus today, up from 28 percent seven years ago, UMass spokesman John Hoey said after the speech.

Kerry congratulated the graduates on their hard work. He said he understood how taxing the demands of jobs and families would become once they establish themselves.

Nevertheless, he urged the Class of 2007 to become politically active, especially where the environment is concerned.

“When I came back from Vietnam, it wasn’t to protest the war,” said Kerry, who was a spokesman for the Vietnam Veterans Against the War.

“It was to take part in Earth Day,” he said, referring to the first Earth Day, in 1970.

“And we went out there 20 million Americans strong, because we were tired of seeing rivers light on fire, tired of seeing toxic chemical sites take over where we should have clean water with wells.”

“Those 20 million people created accountability,” Kerry said: 7 of the 12 congressman known as “the Dirty Dozen,” for their opposition to environmental measures, were defeated, and a barrage of pro-environment legislation was passed.

“We passed the Clean Air Act, the Clean Water Act, the Safe Drinking Water Act, the Marine Mammal Protection Act, the Coastal Zone Management Act, and Richard Nixon signed the Environmental Protection Agency into existence,” Kerry said.

“We didn’t even have that until people went out and made that happen. It wasn’t politicians who gave it to you. It was you who made it happen,” he said

jcastell@projo.com