When the tides are especially high and the swell is running big, waves lick the sea walls of Orange County’s Balboa Island. On a bad day, water cascades over the edge, threatening to flood portions of the 3,300-person isle that, for now, sits a few feet above sea level.

It’s a problem some residents say is worsening as ocean levels rise. Earlier this year, the threat prompted the city of Newport Beach to raise the island’s manmade barrier by nine inches, and city officials are considering a more substantial overhaul that could cost taxpayers upwards of $69 million within two decades to protect the enclave’s multimillion-dollar homes.

But the disagreement over what’s causing the problem – exactly why climate change soon could be literally at the doorsteps of island residents – has become polarizing within the small community. And as neighbors prepare to vote in November’s competitive 48th Congressional District contest, their divergent and oft-voiced views on global warming are a solid predictor of which candidate they support.

Rep. Dana Rohrbacher (R-Costa Mesa), a 30-year incumbent, is facing the toughest fight of his political career, challenged by Democratic real estate executive Harley Rouda, of Laguna Beach, in a race that could shift the national balance of partisan power. Democrats have targeted it as one of at least 23 GOP-held seats they’ll need to flip nationally to take control of the U.S. House of Representatives.

The once soundly-conservative coastal seat, which runs from Laguna Niguel to Seal Beach, is now widely seen as a toss-up. And while the two candidates clash on most of the divisive national issues that are likely to impact the race – including health care and immigration – residents’ views on the environment could play a significant role in who wins.

Both candidates agree that global warming is real. But one, Rohrabacher, argues that humans don’t cause it and shouldn’t be asked to change behaviors or laws in order to prevent it. The other, Rouda, has advocated for curbing carbon emissions and promoting clean energy to fight a potentially existential threat.

Second rate problem

Island homeowner Caroline Wetherington acknowledges that storm surges now run higher than they once did. But, like her congressman, she considers the issue secondary, even a distraction, compared to her concerns over immigration – views that mirror Rohrabacher’s own.

“Dana is supporting (President Donald) Trump’s agenda, and I like what Trump is doing for the economy,” said Wetherington, 54, a real estate broker who recently donated $2,500 to a foundation trying to build a border wall. “As far as sea level rise, I think environmentalists have scammed people.”

Three houses down the block, the politics are markedly different.

There, flies a banner reading “30 years is enough: Say no to Rohrabacher.” Homeowner Maxine Stomber said her congressman’s disbelief that humans are causing climate change poses a direct threat to her neighborhood. She supports Rouda, who has called manmade global warming “arguably the greatest issue facing humankind long term.”

“I’m very concerned about climate change. This is my nest egg,” Stomber, 61, a former Wall Street portfolio manager, said about her island home. “When people say climate change isn’t due to human activity, I think they’re delusional. I’ll believe the scientists.”

The election will come less than two months after the Trump administration issued a report predicting a catastrophic 7-degree rise in global temperatures by 2100 that would submerge coastal cities, and an accompanying decision to stay the course. It also will come after a United Nations report that says man-made climate change by 2040 is likely to destabilize the world’s weather patterns and food supply, amid increased heat waves, floods, and wildfires. That report urged quick, decisive action from global leaders.

Framing the race

The chasm between residents’ views on global warming is characteristic of the stark political divide that pervades the district, where each candidate argues that the other is out of touch with locals.

Rohrabacher, 71, has run on a hard-line anti-illegal immigration platform and called the contest a fight against “an ideological group of leftists who don’t represent our values.” Rouda, 56, a former Republican who decided to run in response to what he saw as partisan dysfunction in Congress, has focused his message on improving the quality and affordability of health care. He also has accused the GOP of deserting historically moderate platforms.

Rohrabacher has employed sharp rhetoric and scare tactics on illegal immigration, similar to Trump. The congressman told the New York Times earlier this year that his constituents “are concerned about illegal immigrants coming into their neighborhood and raping people.” He has attacked Rouda’s support of sanctuary cities. And he has proposed an immigration plan that wouldn’t provide amnesty to anyone in this country illegally and would instate a mandatory e-verify system to check the immigration status of job applicants.

“Our own people are getting shortchanged, especially their children,” Rohrabacher said. “(Rouda) doesn’t understand that.”

Rouda has countered by saying that in 30 years Rohrabacher has done little to reform the nation’s immigration system. The Democrat said if elected, he’d support a plan similar to the bipartisan Senate Bill 744, which would provide a pathway to citizenship for younger immigrants raised in the United States and some others, while also providing $46 billion to bolster border security.

Rouda also emphasizes health care. He supports a tweaked version of the Medicare for All system, in which the government would offer a public health insurance option to compete with private alternatives – a structure he said would cut medical costs. He favors allowing Medicare to negotiate drug prices. And he attacked Rohrabacher for his vote to repeal Obamacare.

“Congressman Rohrabacher has voted 17 times to roll back protections for people with pre-existing conditions,” Rouda said. “That means denying health security… to over 300,000 constituents in CA-48.”

Rohrabacher had denied Rouda’s allegations, and the congressman’s campaign aired TV ads saying he’ll be “fighting for those with pre-existing conditions.” Rohrabacher has proposed a plan to have the federal government pay for all pre-existing health care expenses for those who buy private insurance, while tracking qualifying ailments in a national database. Pressed on how such a system would work, his campaign said details still need to be worked out.

The congressman also has accused Rouda of flip-flopping on his health care plan, noting that the Democrat previously had endorsed a single-payer system. Rouda also has stated publicly that he supported providing federal health care benefits to people who entered the country illegally – something the candidate later denied.

Experience needed?

Part of Rohrabacher’s newfound political vulnerability lies in the fact that he has been frequently mired in controversy.

In May, the National Association of Realtors withdrew support from Rohrabacher after he said that homeowners should be able to refuse to sell their property to gay people. Since 2017, Rohrabacher has met twice with a controversial far-right activist, Charles Johnson, who has questioned the history of the Holocaust and said that “whites may be smarter than blacks.”

The Congressman also has been scrutinized for his defense of Moscow, amid U.S. intelligence officials’ ongoing probe into Kremlin interference in the 2016 election and into allegations of collusion between Russia and the Trump campaign. Rohrabacher, who has opposed economic sanctions against Russia, has publicly rejected U.S. intelligence agencies’ conclusion that Russian operatives hacked the Democratic National Committee in 2016, even after 12 Russian agents were charged in the matter.

It also was recently revealed that Rohrabacher met twice with a woman who federal officials later charged for being an unregistered agent of the Kremlin – basically, an accused Russian spy.

Rohrabacher, a top-ranking member of the House Foreign Affairs’ subcommittee on Europe, Eurasia and Emerging Threats, has said any meetings with Russian operatives were part of his job. He said he advocates only for foreign policies that benefit America and has accused some federal officials of trying to perpetuate a Cold War with Moscow.

Meanwhile, Rohrabacher attacked his opponent’s political inexperience, noting that the Rouda has never held elected office.

“He has had zero public service,” Rohrabacher said. “If I go back to Congress, I’ll have a seniority level that will permit me to accomplish great things.”

Rouda, in turn, has called Rohrabacher inept, noting that the Congressman has passed only three bills in three decades, the last one 14 years ago, and held no committee chairmanships. The Democrat – who finished second among 16 candidates in June primary race – said he wants to make the 48th District a hub for green-energy jobs and technology.

“I’ve been in the private sector my entire life, creating jobs,” Rouda said. “I’m fighting to create better middle-class jobs… I don’t see Dana Rohrabacher doing anything in that regard.”

Rohrabacher defended his track record, saying he doesn’t seek credit for much of his work. He highlighted his role in helping bipartisan efforts to create the county’s water reclamation system, which helps protect locals from drought, and the Santa Ana River Mainstem Project, which has saved some homeowners from paying flood insurance. He also touted his role in helping privatize space flight, which he said brings jobs to the region.

Rising tides

While the political bout rages, large swaths of the 48th are under threat from rising tides and temperatures.

By 2035, parts of Huntington Beach, Seal Beach, Newport Beach, Long Beach, and Marina del Rey could see chronic flooding, according to a 2017 report by the nonprofit Union of Concerned Scientist. This summer, California experienced its hottest July on record.

NASA states on its website that 97 percent or more of climate scientists agree that “climate-warming trends over the past century are extremely likely due to human activities.”

Asked about that threat, Rohrabacher acknowledged that earth might be warming, but said the change is part of natural climate cycles that humans aren’t causing. He said the notion of manmade climate change is a farce, perpetuated by liberal scientists in order to centralize power “in the hands of “the federal government, the global government.”

“I think (issues of immigration and taxes) are certainly more important than the issue of whether humankind is changing the climate of the world,” said Rohrabacher, a longtime member of the House Science committee.

That view hasn’t hurt him in past elections, but it might cost him votes this cycle, even from some Republicans.

Cam Woods, 57, a Balboa Island software engineer, is a long-time registered Republican and fiscal conservative, but has increasingly broken from the party, in part because of what he sees as anti-science policies. In front of his house, he has planted a sign: “Republicans for Harley Rouda for Congress.”

“Being on the water, if sea levels go up a couple of inches, it’s big,” Woods said. “If it goes up a foot, it’s huge.”

But many more of the region’s Republicans seem to agree with their longtime congressman’s views on climate change.

“I don’t call it global warming; I would rather just consider it weather,” said Pamela Hoffman, 75, voter registration chair for the Newport Harbor Republican Women.

“You have other countries like China that are still polluting like crazy. If Americans really tighten our belts, carbon-wise, it’s going to have a small effect,” Hoffman said.

“So, why would everyone in the U.S. live a lesser life when it’s not going to have an impact?”