COLUMBIA, S.C. (AP) — A hard-fought congressional race in South Carolina where Democrats are trying to hold on to a seat they had flipped is too early to call.

U.S. Rep. Joe Cunningham, who became South Carolina’s first new Democrat in Congress since 1992 with his win two years ago, is trying to keep his seat.

Cunningham’s opponent is Republican state House member Nancy Mace, who was the first woman to graduate from The Citadel.

It may be days before all the votes are counted. In Dorchester County, 13,500 mail-in ballots could not be read by scanners because of a printing error. They will need to be entered by hand, and officials would only say they would have that finished by Friday’s deadline to certify results. The district includes some of the more populated portions of the county

Cunningham knew he was in for a tough reelection fight immediately and raised $6 million. Between the Republican primary and the general election, Mace raised more than $4 million, making it by far the costliest U.S. House race in South Carolina history.

The congressional district stretching from Charleston to Hilton Head Island along the state’s coast is richer, more educated and less conservative than much of South Carolina. It also had the smallest gap of any Republican-represented congressional district in the 2016 presidential election, going to the GOP by about 14 percentage points.

Cunningham, 38, worked carefully to build bipartisan support in 2018, getting Republican mayors and other officials in small beach towns to support him by opposing offshore drilling.

Cunningham continued to tout his support by Republicans this year.

Mace, 42, emerged from a four-candidate Republican primary. She ran unsuccessfully for U.S. Senate in her first political race in 2014 before being elected to the South Carolina House twice.

Mace spent the last few weeks of the race trying to make closing Parris Island’s Marine training base near Hilton Head Island an issue.

Cunningham, along with six of South Carolina’s seven Republicans in the U.S. House and Senate supported a military spending bill that requires Parris Island to be able to train both men and women together in five years.

Marine leaders said closing Parris Island and building a new base somewhere else was one of several ideas being considered.

Republican Gov. Henry McMaster joined others in his party in promising the Marines they would do whatever was asked of the state to keep Parris Island open.

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Follow Jeffrey Collins on Twitter at https://twitter.com/JSCollinsAP.

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