OCEAN TOWNSHIP -- When Al Gore stepped on a stage in Monmouth County on Sunday afternoon, the former vice president told the crowd that the word "friendship" is thrown around too loosely in politics.

"But in this case," Gore said, mentioning the man next to him, Democratic New Jersey governor candidate Phil Murphy, "we really have been extremely close friends."

Over the last 20 years, Gore said, he and Murphy's family have vacationed and worked on projects together.

And on Sunday, Gore played the role of cheerleader for Murphy, appearing at a packed campaign rally at the Ocean Township Community Gymnasium as his friend enters the final three-week stretch of the race to succeed outgoing Gov. Chris Christie.

"This is a good man," Gore told the crowd of hundreds about Murphy.

But Gore also played the role of attack dog.

He ripped into both Christie, whose approval ratings have fallen to historic lows in recent months, and Kim Guadagno, Christie's lieutenant governor and Murphy's Republican opponent in the Nov. 7 election.

"Has anybody here been embarrassed by what's gone on here?" Gore, a 69-year-old Tennessee native, asked in his deliberate southern drawl. "Here you have an administration in Trenton and a presidency in Washington, D.C., and sometimes it's kind of hard to take."

"I have been a keen observer of the many, many times of late that New Jersey has been in the news for something the current administration has done," Gore added.

"We're sorry," someone in the audience yelled.

"Don't tell me you're sorry about that," he said. "I'm sorry for you."

Guadagno's campaign did not immediately respond to a message seeking comment.

The visit marked the second time in four days that a former vice president appeared in New Jersey to stump for Murphy. Joe Biden campaigned in Edison on Thursday for Murphy, a former U.S. ambassador to Germany, ex-banking executive, and longtime Democratic fundraiser who is leading Guadagno by double digits in all polls.

On Sunday, Gore continued criticizing Christie by referencing two of the governor's biggest scandals: Beachgate and Bridgegate.

"What direction are we going to go?" Gore asked. "Are the beaches going to be open to all? Are the bridges not going to be used as political punishment?"

"Just remember that political will is itself a renewable resource," he continued. "We need to renew it, we need to feed it, we need nurture it. ... We need to make Phil Murphy the next governor of the state of New Jersey."

Gore -- who has become an outspoken environmentalist since leaving office in 2001 -- also pointed out an upcoming event that many residents in this Jersey Shore town are likely familiar with: the five-year anniversary of Hurricane Sandy.

He noted that it falls shortly after the back-to-back-back hurricanes that ravaged Texas, Florida, and Puerto Rico. And yet, Gore said, President Donald Trump has appointed "climate deniers to all of the important positions."

Gore said Murphy "understands this" -- that he will help battle climate change and improve the state's economy by brining wind turbine and solar jobs to New Jersey.

Gore also pointed out that Murphy's wife, Tammy Murphy, is secretary of the Climate Reality Action Fund, an organization that Gore founded.

Both Murphy and Guadagno vow to return New Jersey to the Regional Greenhouse Gas Initiative, a regional program designed to reduce emissions that Christie yanked the state from in 2011.

Earlier Sunday, Gore appeared with Murphy at a job incubator site in Princeton. The facility, Tigerlabs, promotes tech jobs and innovation, which Gore, citing Thomas Edison and Alexander Graham Bell, argued was once New Jersey's staple export.

"Long before there was anything called Silicon Valley, New Jersey was the technological and innovation center of the United States, and of the world," Gore said. "There's absolutely no reason why committed, passionate, knowledgeable leadership could not bring that legacy back to life in a very meaningful way to create jobs."

Gore and Murphy hosted a 30-minute question-and-answer session with the tech community. And Gore stressed that he doesn't "do many political events" anymore.

"But one of the very good exceptions I make to that rule is (for Murphy)," he said.

Matt Arco may be reached at marco@njadvancemedia.com. Follow him on Twitter @MatthewArco or Facebook.

Brent Johnson may be reached at bjohnson@njadvancemedia.com. Follow him on Twitter @johnsb01. Find NJ.com Politics on Facebook.