Joe Cunningham Martin O'Malley (copy) (copy)

Democratic candidate Joe Cunningham on Tuesday received the backing of the Democratic Congressional Campaign Committee. File/Brad Nettles/Staff

National Democrats say a congressional race in ruby red South Carolina could help them win back control of the House.

The Democratic Congressional Campaign Committee on Tuesday quietly added the state's coastal 1st Congressional District to its "Majority Makers" district list of GOP-held seats the group is targeting in the 2018 midterms.

The fundraising arm of House Democrats grew its list by 9 districts Tuesday afternoon, expanding their political battlegrounds from 47 districts to 56.

South Carolina's 1st District, which spans from Hilton Head Island to McClellanville, is the only congressional race in the state to make the cut.

The designation could provide a national boost to Joe Cunningham, the first-time Democratic congressional candidate who is running against Republican Katie Arrington to represent Charleston in Washington.

Arrington, a one-term Summerville state lawmaker, defeated U.S. Rep. Mark Sanford last month in the Republican primary, handing him his first-ever electoral defeat.

With Arrington's surprise triumph over Sanford — an incumbent with more than two decades of name recognition — the seat is now an open one.

In a statement provided to The Post and Courier, Cunningham said it is a seat he can win.

"We are going to win this race because the people of the Lowcountry are ready for a Congressman who will put country over party and people over politics. From now until Election Day, we plan on talking to every voter from McClellanville to Hilton Head and everywhere in between, and deliver common sense solutions to the issues that affect them every day," Cunningham said. 

A Democrat has not represented South Carolina's 1st Congressional District in nearly 40 years.

DCCC spokeswoman Amanda Sherman said Cunningham is a strong candidate, adding there is "nothing for Republicans to run on but a toxic agenda."

"We believe South Carolina's 1st Congressional District is one to watch in November," Sherman said in a statement provided to The Post and Courier.

Michael Mulè, Arrington's campaign spokesman, said the district will remain a GOP stronghold regardless of the DCCC's involvement. 

"DC Democrats won't find much of an audience for their extremist views like abolishing ICE, having open borders, and encouraging harm to those they disagree with," he said. "The Lowcountry doesn't want Nancy Pelosi, Maxine Waters, and fellow extreme liberal DC Democrats picking their Congressman for them."

This is not the first time the DCCC has shown political interest in the Palmetto State.

In the 2017 special election in the 5th Congressional District, the DCCC invested $275,000 into Democratic congressional candidate Archie Parnell.

Parnell was previously on the Majority Makers list until this spring, when the DCCC refused to support him after divorce records showed he physically abused his ex-wife decades ago.

To win back control of the House, Democrats need to win 23 congressional races in November.

Reach Caitlin Byrd at 843-937-5590 and follow her on Twitter @MaryCaitlinByrd.

Caitlin Byrd is a political reporter at The Post and Courier and author of the Palmetto Politics newsletter. Before moving to Charleston in 2016, her byline appeared in the Asheville Citizen-Times. To date, Byrd has won 17 awards for her work.