In the waning days of her congressional race, Republican Katie Arrington attempted to paint her opponent as a one-issue candidate, concerned only with offshore drilling. 

The issue, however, is likely one of the main forces that helped Democrat Joe Cunningham turn the 1st Congressional District blue for the first time in four decades.

And it may have resonated with an important constituency that Cunningham's staunch opposition to fossil fuel exploration likely spoke to: conservation-minded conservatives.  

"It's a huge group in the 1st District," said outgoing Rep. Mark Sanford. 

Sanford, who lost to Trump loyalist Katie Arrington in a primary for the seat this spring, wrote in a New York Times op-ed last week that the Republican Party should look back to its own conservation history — think Teddy Roosevelt preserving national lands — in a bid to do better in future contests. 

He told The Post and Courier that environmentally aware Republicans exist throughout the state, but especially in the coastal 1st District, where ignoring them would be a blind spot. 

Arrington initially said she stood with the president's plan to open up oil drilling in the Atlantic Ocean, a stance she later backed away from. It's not clear how big an impact that single issue had in the race, but it netted Cunningham the endorsements of three Republican-identifying coastal mayors, and most observers agreed it likely helped him significantly. 

State Sen. Chip Campsen, R-Charleston, said he believed Arrington was being genuine when she clarified her stance on drilling, and it was enough assurance for him to support her.

Campsen, who represents the same coastal communities included in the 1st District, prides himself on his own environmental record. Among other efforts, he drafted the legislation that eventually led to the state's land conservation bank.

However, Campsen said Arrington's reversal may not have been enough for voters. 

"It was too late, probably, too little and too late, to really affect that particular issue," he said. 

In coastal South Carolina, many residents have a deep connection to the land. The complex ecosystem of marshes, creeks and rivers is part of the region's appeal, and the lifestyle, for many, revolves around outdoor activities: hunting, fishing or bird-watching. 

"There’s not the sort of conservative ... reflexive, anti-environment thing we might see in other sort of quote-unquote red states," College of Charleston political scientist Matt Nowlin said. "There is a big outdoor community here that is concerned about environmental issues."

And that history reaches back many years, said Dana Beach, founder of the Coastal Conservation League, a Charleston-based environmental group. 

Part of that history, Beach said, is a long line of field biologists documenting wildlife in the Lowcountry. Famed ornithologists and painters Mark Catesby and John James Audubon both spent part of their careers working from Charleston. 

"It's an embedded part of the culture, I think, to be interested in natural history and to be concerned about it," Beach said.

But in a more modern era, a few notable Republicans from the coastal region have also embodied the coastal relationship with the natural landscape. 

One is Arthur Ravenel Jr., namesake of Charleston's most iconic bridge, who also diverged from the GOP on environmental matters when he represented the 1st District, from 1987 to 1995. 

"Arthur Ravenel probably did as much as anybody to make it safe for conservatives to be conservationists," said Beach, who served as a staffer for Ravenel before founding CCL.

Campsen has also made a point of pushing for conservation through free-market incentives, he said, in part because of his own connection to the natural landscape. His impetus for opposing offshore drilling isn't just the possibility of a spill, as with many other coastal Republicans — he's skeptical that the coastline could support the industry necessary to build and maintain drilling infrastructure. 

The issue, he said, is bipartisan.

"It's a big-tent conservation in South Carolina," Campsen said. "It's not Republican, it's not Democrat, it's a big tent. You’ll find some of the most conservative Republicans who are coalescing with environmental groups to help preserve the natural resources that we have, and you really develop some momentum."

There's also Sanford's own environmental record. As governor, he also supported the conservation bank, which he has cited as among his proudest accomplishments.

In September, Sanford made a public plea for Congress to maintain the federal Land and Water Conservation Fund, which President Trump's budget had targeted for a 90 percent cut.

Sanford also has opposed oil drilling and is pushing to create an expansive public park on Daniel Island.

It remains unclear, however, whether the politician who once was considered unbeatable, with waning time left in office, will see his latest conservation effort through. 

Caitlin Byrd contributed to this article. 

Reach Chloe Johnson at 843-735-9985. Follow her on Twitter @_ChloeAJ.