Nuclear power once was the greenie’s ultimate litmus test.

Pro-nuke? You must have been an industry toady willing to relegate future generations to radioactive Armageddon. Anti-nuke? You must have righteously understood that the only future to sense in our world would be one graced with windmills, solar panels, peace, love and flowers.

If environmentalism were a religion, the nuclear industry was its devil -- creepier even than Exxon-Mobil.

Now, at least for some environmental activists and for a lot of environmental allies, nuclear power is the lesser of two evils. Climate change is the worser.

How much less politically radioactive nuclear power has become was underscored Oct. 11 in a Sunday New York Times op-ed co-written by Sen. John Kerry. As Massachusetts’ lieutenant governor and then as senator, the Democrat was a vocal foe of the Seabrook nuclear power plant, then under construction in neighboring New Hampshire. He remains an environmental darling -- the climate-change bill co-author tasked with rounding up Senate supporters of the historic legislation.

The NYT op-ed generated buzz because Kerry wrote it with a Republican colleague, Lindsay Graham of South Carolina. It signaled that some Republicans actually might support a climate bill this year if it contained significant compromises, and that Democrats might agree to such compromises to get the bill passed.

A lot of those compromises have to do with nukes. In the article, Kerry and Graham argue that nuclear power must be part of the mix in addressing climate change. Not only that, they say, nukes deserve special favors. “While we invest in renewable energy sources like wind and solar,” they write:

"... we must also take advantage of nuclear power, our single largest contributor of emissions-free power. Nuclear power needs to be a core component of electricity generation if we are to meet our emission reduction targets. We need to jettison cumbersome regulations that have stalled the construction of nuclear plants in favor of a streamlined permit system that maintains vigorous safeguards while allowing utilities to secure financing for more plants. We must also do more to encourage serious investment in research and development to find solutions to our nuclear waste problem."

In many ways, Kerry’s support for nuclear subsidies demonstrates just how desperately he and others view the prospect of climate change. It’s not that nuclear plants have become any safer. There are still myriad questions surrounding them: Where will we dispose of the waste? How can we find enough water to cool them? What about the terrorist threat? What about the prospect of nuclear proliferation? And how can we justify subsidizing loan guarantees and insurance backups for a wealthy industry surrounded by so many questions?

But as the nuclear industry’s twin bête noires -- the Chernobyl disaster and the Three Mile Island accident -- fade from memory, the threat of climate change looms larger and scarier. Nuclear power, its advocates note, pumps virtually no greenhouse gases to the atmosphere.

The whole new reality creates quite a predicament for environmentalists. Yes, politics does make strange bedfellows, but usually they don’t require Geiger counters. The nuclear industry’s lead trade group, the Nuclear Energy Institute (NEI), owns an appropriate reputation for greenwashing PR on the order of the American Coalition for Clean Coal Energy.

In the typical doublespeak fashion of moneyed Washington special interests, NEI has crafted slick marketing campaigns to appropriate the phrase “clean energy.” It backs an industry front group called the “Clean and Safe Energy Coalition” and a speakers’ bureau called Clean Energy America. With the start of this year’s National Hockey League season, NEI struck a sponsorship deal with the Washington Capitals; there’s nothing like rink-side signs that say “Clean Air Energy” to get your message across to members of Congress who happen to be hockey fans.

Most environmental organizations still argue against the increased subsidies needed to kick-start nuclear power plants. Among the foes are Clean Water Action, Environmental Working Group, Greenpeace, Physicians for Social Responsibility, Public Citizen and the Sierra Club. They note that steering resources into safer, renewable energy -- such as wind, solar and conservation -- seems to bode better for both the environment and for the economy.

The anti-nuclear movement still has strong pop-cultural pull among environmentalists. Last week, -- a group backed by Jackson Brown, Bonnie Raitt and other celebrities -- organized a “National Call In Day” to pressure Congress not to include nuclear subsidies in climate legislation.

Other environmental groups shouldn’t be described exactly as pro-nuke, but they are keeping their options open. The Environmental Defense Fund, the Natural Resources Defense Council and the Union of Concerned Scientists -- all highly respected organizations with a strong bent toward research and policies -- have said they’re at least willing to consider nuclear energy as part of broader legislation.

The thing is that the Senate climate change bill introduced last month by Kerry and Sen. Barbara Boxer already contains quite a few gifts for the nuclear industry, including job training, regulatory reform, subsidies and $18.5 billion in loan guarantees. That’s more generous than the House-approved Waxman-Markey bill. (For more on this, visit MNN’s politics channel.)

So the compromises create yet another predicament for environmentalists. If the climate legislation ends up so much more generous to the nuclear energy than it is to emerging renewable industries -- such as wind, solar and conservation -- some will have to consider whether to withdraw their support, and to rely on the Environmental Protection Agency to push for regulation.

Either that, or strike their deal with the devil.

Journalist Ken Edelstein writes the Media Mayhem column for the Mother Nature Network. From various coffee shops in Atlanta, he publishes an environmental news site at