LONDONDERRY – Joe Biden may be losing some ground as the Democratic frontrunner, but that hardly seemed the case as he slammed Donald Trump, defended Obamacare and spoke about climate change at a rally on Saturday in Londonderry.

A recent poll shows Biden with the support of 26% of voters who say they will vote in next year’s Democratic primaries or caucuses, while 19% back U.S. Sen. Elizabeth Warren.

U.S. Sens. Kamala Harris and Bernie Sanders round out the top four, tied at 13%.

Biden said the first thing he would do as president is immediately rejoin the Paris Climate Accord.

“When we did that, we wrote in a provision that every two years, you have to up its ante – you have to raise the standards,” he said. “They’re not being raised now. We’re the only nation that can lead the world to get it done.”

He also defended the Affordable Care Act, saying that while Trump is “quietly” trying to dismantle Obamacare, he believes we should build on it.

“When we passed the Affordable Care Act, I told the president it was a pretty big deal, or something to that effect,” he joked. “I was never more proud than in that moment. It was a huge leap. He got it done.”

Biden added that Trump is morally wrong as he tried to make the Affordable Care Act unconstitutional.

“We should provide a public option,” he said. “I’m against anyone who wants to do away with it and start over. Trump doesn’t understand that repealing Obamacare is one of the worst things he could do to deal with the opioid crisis. And that just goes to show how much he doesn’t know.”

Biden called for the end of fear, and the call for hope.

“We need to unify the nation,” he said. “I find it fascinating that people say, ‘well, it can’t be done.’ Let me tell you, if it can’t be done, we’re done. We’re in real trouble. This vicious, ugly, mean political environment we live in, is one that the Constitution is not designed to deal with.”

He wrapped up his speech, saying, “We choose unity over division. We choose science over fiction. And I promise you, we’re going to choose truth over lies.”