Climate change has been elevated during the Democratic presidential primary campaign like never before, and that must continue in the general election for Hillary Clinton to defeat Donald Trump, an environmental leader said Thursday.

Gene Karpinski, president of the League of Conservation Voters, said climate change needs to be kept on the forefront of policy debates during the general election. For those who care about the climate, an issue that resonates well with independent voters, the former secretary of state must be the choice for president, he said.