PHILADELPHIA -- Hillary Clinton raced into a sharpening phase of her campaign last night by appealing to anxious Americans in hardscrabble coal towns and Texas borderlands, in the first address by a female major-party nominee for president in U.S. history.

Clinton challenged rival Donald Trump on his honesty, temperament and empathy in the pointed speech to an unbridled audience that waved American flags and chanted "Hillary, Hillary, Hillary." She also described a nation in pain, with too much poverty and unemployment, while promising to fight for disaffected workers, maligned immigrants and underpaid women.

"A man you can bait with a tweet is not a man we can trust with nuclear weapons," Clinton said.

Referring to Trump's comments questioning the presence of climate change, she said, "And I believe in science," prompting an eruption of applause. She also confronted Trump's assertion that he would repeal the Paris climate agreement, by saying she's "proud" of the United States' participation in the pact finalized last December.

"I believe that climate change is real and that we can save our planet while creating millions of good-paying clean energy jobs," Clinton said. "I believe that when we have millions of hardworking immigrants contributing to our economy, it would be self-defeating and inhumane to kick them out."

Clinton delivered a populist and inclusive message with promises to make job creation her top priority. But she also embraced the historic moment created by her nomination.

"Standing here as my mother's daughter, and my daughter's mother, I'm so happy this day has come," she said, "happy for grandmothers and little girls and everyone in between. Happy for boys and men, too -- because when any barrier falls in America, for anyone, it clears the way for everyone."

Moments before Clinton spoke, her daughter, Chelsea, made an appeal to the audience to see her mother in personal terms. She also sought to repair disunity between the liberal and moderate wings of the party.

"I'm voting for the progressive who will protect our planet from climate change and our communities from gun violence, who will reform our criminal justice system, and who believes that women's rights are human rights, and LGBT rights are human rights," Chelsea Clinton said.

Celebrities and a hoax

The four-day convention propels Clinton into the final stretch of a presidential race that's featuring emotional issues like immigration, crime and income inequality. The Democratic National Convention elevated climate change on the party's list of electoral priorities, a move that's meant to energize progressive voters while casting shadows on Trump's judgment related to science and the environment.

The convention, held at the Wells Fargo Center, a professional basketball arena in the southern outskirts of the city, included appearances last night by celebrities Katy Perry, Kareem Abdul-Jabbar, Sheila E., and Carole King. The lineup also touched on the issue of addressing rising temperatures, a theme that was weaved throughout the convention.

"Climate change is happening now. Yet Donald Trump calls it -- and I quote -- a 'hoax,'" Gene Karpinski, president of the League of Conservation Voters, said in an address to delegates yesterday. "And more than just deny it, his policies would make climate change worse."

Before his address, Karpinski shared a detail about his wardrobe. His tie was a tribute to Jerry Garcia, the late Grateful Dead singer, and is named "Green Landscape." "Perfect," Karpinski said.

On the floor of the arena, where delegates sat shoulder-to-shoulder in folding chairs, famous politicians mixed with local activists. Former Louisiana Sen. Mary Landrieu (D) sat next to a walkway clogged with delegates and reporters, as police officers shouted orders to keep moving. Cable news anchors sat at elevated desks under bright lights; they were within arm's reach of passersby.

Sometimes the faces of forgotten politicians punctuated the crowded floor.

Former California Gov. Gray Davis (D), whose approval rating plummeted following weeks of rolling blackouts in 2000 and 2001, for which Enron and other energy traders were later blamed, said humans are "killing the climate." He said renewable fuels for electricity and transportation could be deployed "fairly quickly" to reduce emissions.

He drew the line at trading the Clean Power Plan, President Obama's regulatory program aimed at power plants, for a federal carbon tax, saying more than one program is needed to cut emissions. Indeed, he only reluctantly said he would support a carbon tax, explaining that he shrinks from new taxes.

"If you forced me to vote yes or no, I would vote yes," Davis said of a carbon tax.

Clean power what?

The Clean Power Plan, which requires utilities nationwide to cut their carbon emissions 32 percent by 2030, is the cornerstone of Obama's efforts to address climate change. It was instrumental in convincing world leaders that the United States could reduce greenhouse gases without congressional cooperation. That helped U.S. negotiators finalize the Paris climate agreement.

But many delegates here feel that too little action is being taken to address global warming. More than a dozen delegates support stronger actions, like a carbon tax. And many didn't know what the Clean Power Plan was when asked about it.

"Absolutely, because we have so much catching up to do," Tom Anderson, a Louisiana delegate, said of a carbon tax. "We gotta tax something to take care of our environment and our climate, or we're a lost planet."

He wasn't familiar with the Clean Power Plan.

"I think it makes sense, you know, helping people go green," said Illinois delegate Brad Ellis of taxing carbon. "The problem with it is it get passed on to the consumers."

Ellis, who was wearing a Chicago Bears jersey, hadn't heard of the Clean Power Plan.

Brian Whitecalf, a Nebraska delegate, likes the idea of taxing carbon, but he said it should be called a "fee" to avoid political obstacles.

Asked about the Clean Power Plan, he said, "Is that clean coal?"

It's not surprising that voters, or even some delegates, the most active members of the party, are unfamiliar with the details of regulating greenhouse gases, said Paul Bledsoe, an energy consultant and a former climate aide in the Clinton White House.

"They just want to be sure the climate is being protected," said Bledsoe, who believes Democrats should be saying more about climate change than they already are. "It's time to take the gloves off, on climate and many other issues, and dramatically illustrate how radically out of the mainstream Republicans and Trump really are."

Clinton sketched out a plan for her first 100 days in office, saying she would work with Republicans to create "the biggest investment in new, good-paying jobs since World War II."

"Jobs in manufacturing, clean energy, technology and innovation, small business, and infrastructure," she said. "If we invest in infrastructure now, we'll not only create jobs today, but lay the foundation for the jobs of the future."

Reporters Josh Kurtz, Manuel Quiñones and George Cahlink contributed.

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC., 202-628-6500