Last week, a small but influential online magazine that follows energy and environmental issues noted a slight shift in the Washington pecking order.

U.S. Sen. Johnny Isakson, R-Ga., has been placed in charge of the survival of nuclear energy in the United States, E&E Daily reported. Isakson inherits the informal position from his Senate colleagues in South Carolina, where utilities decided to abandon the construction of two nuclear reactors.

The cancellation leaves just two new nuclear units being built in the United States — both a part of the Plant Vogtle expansion in east Georgia.

“We’re kind of the last of the Indians here, with South Carolina dropping out,” Isakson said via telephone this week. “We’re not only the lead dog – we’re the only dog.”

If you follow Georgia politics, you’re probably aware of the two election cycles currently in play. Leadership contests in Georgia cities will resolve themselves in November or, as is likely in Atlanta mayor’s race, with a December runoff.

Then there’s the 2018 race for governor and other state elections. A first culling will come with the May primaries.

But there’s a third campaign in between – the fight over Georgia Power’s decision to continue the construction of two new nuclear reactors. The Vogtle expansion was already more than three years behind schedule and $3 billion over budget when its key contractor, Westinghouse Electric, filed bankruptcy in March.

The campaign to save the Vogtle expansion — or kill it — has two legs. The state Public Service Commission voted last week to begin a review of Georgia Power’s plan to keep going that will culminate with an up-or-down vote in February.

Georgia Power presents its case in November. Opponents have their say in December.

Then there’s the fight in D.C. that Isakson now has charge of, which is likely to play out in the final days of 2017.

Georgia Power and other sponsors of the Vogtle expansion are eligible for an $800 million tax credit if the reactors are up and operating by Jan. 1, 2021.

The tax credit is essential to making the expansion economically viable. But hope of meeting that deadline has dried up. Georgia Power says the new reactors will be operational by late 2022, at a cost of $28 billion — about double the original estimate.

Isakson said he’s likely to tack an extension for the nuclear energy tax credit to “catch-all” legislation in late December, perhaps coupled with tax breaks targeted for wind, solar or biomass interests.

“There are plenty of opportunities. There are also plenty of folks who have an interest in tax credits in the Senate who will need help getting theirs through,’ Isakson said. “I know who they are and where some of them live.”

Isakson’s new role as a protector of nuclear power has an element of karma. In the early 1980s, at the beginning of his political career and when he first became the House minority leader in the state Capitol, Isakson was a key supporter of legislation that allowed the first nuclear reactors at Plant Vogtle to be built.

So it’s no surprise that, like Gov. Nathan Deal, Isakson is giving full-throated support to Georgia Power’s decision to persevere. “To let what’s been done go to the wayside would be a tremendous injustice for our people,” Isakson said.

The political hazard is ratepayer resentment. Georgia Power customers have paid roughly $4 billion in surcharges to cover financing costs associated with Plant Vogtle — an advance payment made possible in 2009 by the Legislature.

All five members of the PSC are Republican. Two members, Chairman Stan Wise and Chuck Eaton, are up for re-election in November 2018.

But advocates for continuing construction of the two new Vogtle reactors got some good news on Monday.

Over the last few months, utilities with aging nuclear reactors in several states – Ohio, Pennsylvania and New Jersey included — have found themselves under increased economic pressure from cheap natural gas, and have sought direct state subsidies.

In each case, environmentalists and consumer advocates have voiced concern, but it has been the American Petroleum Institute, a trade organization that also represents the fracking industry, that has largely financed the opposition.

PSC Chairman Wise said he's been told the API does not plan to participate in the debate over Vogtle — which means that opponents of the Vogtle expansion will have to look elsewhere for cash.

Another development has also emerged over the last few months that could bode well for Vogtle supporters. We’ve seen Democrats attempt to nationalize the Sixth District congressional contest in Georgia. Democrat Stacey Abrams aims to do the same in next year’s gubernatorial contest.

Plant Vogtle supporters are following suit. They're not abandoning their arguments for cheap, locally produced energy, but they're also invoking the name of Vladimir Putin.

Keeping up this country’s nuclear expertise is essential to blocking the spread of nuclear weapons, argues Michael Shellenberger, co-founder of Breakthrough Institute, a think tank that focuses on environmental issues. He supports the expansion of nuclear power as an answer to climate change, but has also begun to argue that U.S. influence abroad is at stake, too.

“The United States has been really the leader and pioneer of creating teams and human infrastructure – nuclear cops at the [International Energy Agency] and elsewhere — to prevent any diversion of materials for weapons,” Shellenberger said.

“Nuclear energy isn’t going anywhere,” he said. “The Russians and the Chinese are going to dominate that market. So then it becomes a question of how concerned are you that the Russians and Chinese will be as effective as the United States has been in preventing the spread of weapons.”

At least one PSC member, Tim Echols, has echoed these sentiments. And Isakson said the national security argument is giving him additional traction in Washington.

Nuclear expertise, he said, is devolving on “Russia, China and a lot of other people who aren’t our friends.

“All the nuclear component parts – all the stuff is built in Japan and other places around the world. They’re not built in the United States,” Isakson said.

And that, friends, is the unfinished tale of an American nuclear renaissance that is close to going bust.