(1) The EPA releases a draft tailoring rule which will give the agency a framework for regulating carbon dioxide and GHG emissions by heavy industrial emitters in the U.S.
(2) Senators Kerry, Graham and Lieberman begin work on a revised version of climate change/cap-and-trade/environmental protection (what ever the word du jour is) legislation - rumored to include a provision which would hamstring the EPA's ability to regulate carbon emissions.
(3) The EPA submits its draft tailoring rule to the White House for final review, indicating that its finalizing and formal release could be imminent (per EPA Administrator Lisa Jackson, most likely in May).
(4) Senate Majority Leader Reid - in a desperate gambit to save his seat in the November elections - shifts the priorities of the Senate legislative calendar from climate change to immigration reform.
(5) Senator Graham, angry at the sudden switch from climate to immigration, withdraws from negotiations, putting an indefinite pause on moving the legislation forward - and blocking the provision preventing the EPA from exercising oversight.
In the few days since Graham pulled back, there have been numerous columnists and bloggers theorizing that he took this action because of pressure from Republican leadership. I'm not sure I agree, and here's a wild theory I've come up with along those lines: he pulled out because of White House pressure. While the President publicly says climate change legislation remains a priority, could he privately want the authority to regulate heavy emitters in the hands of the Executive Branch? By pressuring the one Republican senator willing to negotiate on the Senate legislation (or was he promised something in return?) to step aside, the Administration could potentially have killed the bill and the provision taking away EPA oversight.
So perhaps everyone gets what they want: Graham gets some sort of payoff later on; Reid gets his immigration bill and (presumably) secures his reelection; and the Administration gets to control a big sector of American manufacturing. Far-fetched? Perhaps - but certainly plausible...