Hillary Rodham Clinton has selected a longtime aide to Rep. James Clyburn (D-S.C.) to run her South Carolina primary campaign, according to Democratic officials familiar with the move.

Clay Middleton, a grassroots political organizer in South Carolina with deep ties in the state's African American, faith and military communities, is slated to serve as Clinton's South Carolina state director and oversee her first-in-the-South primary campaign.

Richard W. Riley, a former governor who served as secretary of education in former president Bill Clinton's cabinet, has taken a leadership role behind-the-scenes in preparing for Clinton's South Carolina campaign, the sources said. Riley was an active Clinton supporter in 2008 and is likely to serve as state chairman.

The selection of Middleton was confirmed by several Democratic officials who requested anonymity because they were not authorized to discuss the matter. Middleton could not be reached for comment and a Clinton spokesman declined to comment.

Middleton currently serves in the Obama administration as a senior adviser at the Department of Energy, according to his LinkedIn profile. He previously served for eight years on the staff of Clyburn, the No. 3 Democrat in the House and South Carolina's most powerful Democratic figure. He also has worked for the state Democratic Party and on Obama's 2008 campaign.

A major in the South Carolina Army National Guard and graduate of The Citadel, Middleton has a military background and has a reputation as a skilled field organizer. Middleton, who is black, is highly regarded by the state's African American leaders and has connections to many of the churches that historically have played an important role in Democratic voter turnout.

In 2008,Obama beat Clinton badly in South Carolina. Clinton's allies in South Carolina said she will need to rebuild ties to black voters, who are expected to make up between 50 percent and 60 percent of the primary electorate.

Dan Balz and Anne Gearan contributed to this report.