Attorneys argued that using 1,800 acres on the Savannah River to develop jobs in an impoverished area is a valid public use.
The county plans to lease the land for $350 million to Stevedoring Services of America for a shipping terminal on the site on the Savannah River.
"We're out there negotiating a deal which is good for our county," attorney Gedney Howe said Wednesday.
Attorneys for the state of Georgia say that's not a public use for the land, which is now used by the U.S. Army Corps of Engineers for disposing of silt from dredging the harbor channel.
The land cannot be condemned for private use, said Richard Bybee, who is representing the Georgia Department of Transportation.
"We think that's what's going on here because Jasper County doesn't control the project," Bybee said after the hearing. "That doesn't muster under South Carolina law."
The question for the court is not whether Jasper County needs jobs, but whether or not the county can use "considerable economic need" as justification for condemning the land, Chief Justice Jean Toal told Howe.
Over 40 percent of Jasper County residents now leave the county for work, many in nearby Savannah, Howe said.
That's not a satisfactory condition for Jasper residents, and they wanted their public officials to do something to alter it, Howe said.
But a 1978 case -- the precedent-setting Karesh v. City Council of Charleston -- the court ruled against the city of Charleston, which had condemned land for private development. Jasper County's decision to condemn the land to make room for a port has striking similarities to the 1978 case.
"As I see it, your biggest hurdle is to get around the Karesh case," Supreme Court Justice James E. Moore told attorneys at the Columbia hearing.
In the Karesh case, Charleston was forced to restructure its financing to accord with the Supreme Court's ruling before the project could move forward. The city now owns the parking garage that includes a hotel and conference center.
If the high court takes similar action in this case, Jasper County would consider holding a referendum to make the port a public project, Jasper County attorney Tom Johnson said after Wednesday's hearing. The matter could be put to a referendum to see if voters would raise the money necessary, he said.
The case came to the Supreme Court when Georgia Transportation officials appealed a ruling by a lower court judge in April.
Circuit Court Judge Perry Buckner said building a shipping terminal on the Georgia-owned property would amount to a public use.
Buckner said a steamship terminal would create jobs representing almost 40 percent of the gross value of the Jasper tax base, which now relies heavily on tourism and service jobs.
Because the county has signed a lease with the company, the county could be seen legally as the operator of the shipping terminal, Buckner said.