WASHINGTON — When election time comes next year, Will Galloway, a student and Republican youth leader at Clemson University, will look for candidates who are strong on the mainstream conservative causes he cares about most, including gun rights and opposing abortion.
But there is another issue high on his list of urgent concerns that is not on his party’s agenda: climate change.
“Climate change isn’t going to discriminate between red states and blue states, so red-state actors have to start engaging on these issues,” said Mr. Galloway, 19, who is heading into his sophomore year and is chairman of the South Carolina Federation of College Republicans. “But we haven’t been. We’ve completely ceded them to the left.”
While Donald Trump has led the Republican Party far down the road of denying the scientific consensus of human-caused climate change, Mr. Galloway represents a concern among younger Republicans that has caught the attention of Republican strategists.
In conversations with 10 G.O.P. analysts, consultants and activists, all said they were acutely aware of the rising influence of young voters like Mr. Galloway, who have never lived through a colder-than-average month and identify climate change as a top priority. Those strategists said lawmakers were aware, too, but few were taking action.
“We’re definitely sending a message to younger voters that we don’t care about things that are very important to them,” said Douglas Heye, a former communications director at the Republican National Committee. “This spells certain doom in the long term if there isn’t a plan to admit reality and have legislative prescriptions for it.”
President Trump has set the tone for Republicans by deriding climate change, using White House resources to undermine science and avoiding even uttering the phrase. Outside of a handful of states such as Florida, where addressing climate change has become more bipartisan, analysts said Republican politicians were unlikely to buck Mr. Trump or even to talk about climate change on the campaign trail at all, except perhaps to criticize Democrats for supporting the Green New Deal.
That, several strategists warned, means the party stands to lose voters to Democrats in 2020 and beyond — a prospect they said was particularly worrisome in swing districts that Republicans must win to recapture a majority in the House of Representatives.
The polling bears out Mr. Heye’s prediction of a backlash. Nearly 60 percent of Republicans between the ages of 23 and 38 say that climate change is having an effect on the United States, and 36 percent believe humans are the cause. That’s about double the numbers of Republicans over age 52.
But younger generations are also now outvoting their elders. According to a Pew Research Center analysis, voters under the age of 53 cast 62.5 million votes in the 2018 midterm elections. Those 53 and older, by contrast, were responsible for 60.1 million votes.
“Americans believe climate change is real, and that number goes up every single month,” Frank Luntz, a veteran Republican strategist, told a Congressional panel recently. He also circulated a memo to congressional Republicans in June warning that climate change was “a G.O.P. vulnerability and a G.O.P. opportunity.”
A new Harvard University survey of voters under the age of 30 found that 73 percent of respondents disapproved of Mr. Trump’s approach to climate change (about the same proportion as those who object to his handling of race relations). Half the respondents identified as Republican or independent.
“Here’s another gap between our party and younger voters,” said a recent report by a Republican polling firm, Public Opinion Strategies. Speaking of younger Republicans, the firm concluded that “climate change is their most important issue” and called the numbers “concerning” for the party’s future.
The full effect quite likely will not be felt until after the 2020 election cycle. President Trump’s campaign appears to have identified a strategy for winning re-election that relies on polarizing the electorate on issues like race, immigration and, it seems, climate change. But conservatives said the long term implications of that gambit were worrisome for the future of the party and the planet.
“He gets to set the national platform,” Joseph Majkut, director of climate policy at the Niskanen Center, a center-right research organization, said of Mr. Trump. But, he noted, “Every year that goes by, where people are going about their lives as if greenhouse gas emissions are a matter of very small concern, we make the problem worse for ourselves.”
Mr. Galloway and 45 other young Republicans with the American Conservation Coalition, a group that advocates for conservative environmental policies, brought that message to Washington last month when they lobbied Congress to address greenhouse gas emissions with free-market solutions.
“You can be skeptical of climate change all you want, but young people aren’t, and there’s no way conservatives are going to win elections if we don’t deal with climate change,” said Benjamin Backer, 21, the coalition’s founder and president.
Mr. Backer said he was encouraged by Mr. Trump’s environmental speech on July 8 as well as recent moves among some Republicans in Congress to advance climate policies. But he also said changes were not occurring fast enough to lure his generation of environmentally conscious conservatives.
“There’s a lot of people out there who would probably vote Republican if they knew there was a conservative agenda on climate change,” Mr. Backer said. Instead, he said, “They’re going to go to the Democratic Party, because that’s the only party that’s talking about the environment.”
Mr. Trump’s core supporters say they’re not worried. Standing in the sweltering heat outside East Carolina University in Greenville, N.C., last month as he waited for entry into a rally led by the president, Trey Bagley, 25, readily acknowledged climate science. But Mr. Bagley, a sergeant in the Marine Corps Reserves wearing a “Trump 2020, Make Liberals Cry Again” shirt said that did not make him a Democrat.
“I completely agree that we’re offending the climate,” Mr. Bagley said. “But the solutions that are being introduced to fix it are going to drive us back into the Dark Ages.”
He’s not alone in that belief. To illustrate that, Alex Flint, executive director of the Alliance for Market Solutions, a conservative nonprofit group that advocates for a carbon tax, hit play on a video of 11 Trump voters around a hotel conference table in Florida discussing climate change. Government can’t be trusted to solve climate change, the focus group agreed. But like Mr. Bagley, they also all agreed that climate change is real.
“Republican orthodoxy is changing,” Mr. Flint said. “You’re safe saying you acknowledge climate change.”
He said climate change is hardly a top-tier topic among even moderate Republicans. But he noted it is a key differential issue in swing districts that can either help a candidate win young, college educated and female voters, or lose them.
“It’s a matter of honesty,” he said. “Voters believe it is happening, at the very least, they want their politicians to acknowledge reality.”
Scott Jennings, a Republican consultant and a former campaign adviser to Senator Mitch McConnell of Kentucky, said 2020 candidates in different states would take various approaches to climate change, but he predicted that most would focus on simply attacking Democrats and the Green New Deal.
Still, he said, “Someday Republicans are going to have to come up with some proposals that are responsive to these issues and, frankly, be more reasonable and more thoughtful.”
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