Mayor Kasim Reed compared the potential economic impact to action by one of his predecessors that led to creation of the state's largest economic engine, Hartsfield-Jackson Atlanta International Airport.
"Who would have thought, when the leaders back then made the decision around Hartsfield-Jackson, that we would sit here, hosting 92 million passengers a year?" Reed said.
His comments came after a ceremony celebrating the groundbreaking of Porsche's North American headquarters next to the massive airport, the world's busiest.
Reed acknowledges it's too soon to draft a timetable for the rail link, saying the first step is to begin a public conversation. With federal funds available from states that changed their minds about their own rail projects, Georgia could move to the head of the line, he said.
The deepening of the ship's channel in the Savannah River to accommodate larger freighters will catapult the state's economy to a new level, he predicted. And he sees advantages for both Atlanta and Georgia as a whole if various parts of the state capitalize on it.
"Georgia's going to have to have a number of dynamic economies, not just in the city of Atlanta but throughout the state. Savannah has all of the bones for it. It has a great personality. It has its own character," he said. "People don't have any idea what we're at the beginning of with the deepening of the port."
Gov. Nathan Deal was at the same event but expressed less urgency about the rail proposal.
"In the short term, the things that I'm most focused on is dealing with the congestion here in Atlanta," he said.
He is talking with the Department of Transportation about adding lanes to Atlanta highways over the next few years to ease automotive traffic snarls.
If cars are the immediate concern, trucks are the long-range focus.
"A little more long term, now that we have good news on the port and are moving forward with that deepening project, we have to give serious consideration to what we're going to do with that increased truck traffic," Deal added.
He is considering special, truck-only lanes and alternative routes away from the high-volume car corridors.
But he isn't dismissing Reed or his ideas.
"The reason he does this is because he recognizes it's not only good for the state but also for the city of Atlanta," Deal said.
The two say they're friends although Deal is a Republican and Reed is a Democrat. They have often gone to Washington together to lobby for state issues, especially federal funding of the river deepening.