"That is not an earmark. That's a constitutional responsibility," he told a luncheon hosted by the Atlanta Press Club. "It is not a Georgia issue. It's critical to the economy of the United States."
The Senator, who won re-election last November, hailed the port as the fastest-growing containerized-freight port in the nation. That makes it a major economic asset, he said.
"There is a difference between an investment and an expenditure," he said, adding that he considers digging the river channel to feet is an investment.
A University of Georgia study estimates that roughly every seventh job in the state is connected with shipping cargo through the port.
Asked his view of a proposal President Obama is expected to announce tonight in his State of the Union Address about creating an infrastructure bank, Isakson was lukewarm. He said the president should focus on cutting spending.
Isakson, a Republican, agrees with GOP efforts to tie a March vote on raising the country's debt limit to spending cuts.
"It would be morally irresponsible to raise the debt limit without extracting commitments to cut spending," he said.
Isakson's speech primarily focused on the need to control federal spending. Some critics have targeted the $600 million harbor deepening as a pork-barrel project.
Isakson countered that a study by the U. S. Corps of Engineers found it to have one of the most positive cost-benefit paybacks.
Reach Walter C. Jonesat email@example.com.