Activists are quietly forging ahead with their campaign for carbon taxes despite long odds on Capitol Hill.

Bob Inglis, a former GOP House member from South Carolina, is part of a very loose collection of policy wonks and advocates fighting to change the politics of taxing emissions.

“It’s a longer-term play here,” Inglis said.

Inglis, who launched the “Energy and Enterprise Initiative” at George Mason University last year, sees several forces converging that will enable a carbon tax to surface in a broader fiscal policy deal.

It would happen, he said, by “immaculate conception,” but not until 2015 or 2016.