There's two ways that an ongoing program  to regulate greenhouse gases by the U.S. Environmental Protection Agency (EPA) could get shut down this week by Congress or the White House.
The first is through straight legislation. For a week, Senate Majority Leader Harry Reid (D-NV) has been vowing to hold a vote on Senate measures to limit EPA's ability to control the gases. The measures are amendments to a small-business bill , which is virtually guaranteed a vote. The leading measure is an amendment  authored by Senate Minority Leader Mitch McConnell (R-KY) and Senator Jim Inhofe (R-OK) that would nullify previous efforts to scientifically define greenhouse gases as "endangering health and welfare" and to implement the program.
The question is whether the Senate measure will receive the 60 votes needed to move ahead. The House of Representatives is expected to pass identical legislation. President Barack Obama has vowed to veto the legislation, despite the political problems arising from rejecting a bill meant to help small businesses, including a provision to extend a long-running research program paid with a tax on federal research agencies.
The second way that EPA could be stopped is by adding a so-called rider to the 2011 spending bill being negotiated this week. The language would bar the agency from spending money to implement the regulations. The House approved such a ban in February in its version of the spending bill, but on Friday Reid said that "neither the White House nor Senate Leaders is going to accept any EPA riders."
Last week, as Glenn Hurowitz laid out , the White House appeared ambivalent on the EPA greenhouse gas language in the bill, with rumors that it was telling Democrats to accept the limitations on the agency as part of the budget negotiations. It was never clear how real the rumors were. In any event, major environmental groups pushed back, Hurowitz said:
"Obama to Sell Out the EPA?" —Sierra Club e-mail blast from Conservation Director Sarah Hodgdon
"Tell Obama & Reid: Don't Cave to Polluters" —League of Conservation Voters (LCV) Executive Director Gene Karpinski
"At EDF, our position is that children's health should not be a bargaining chip." —Environmental Defense Fund (EDF) President Fred Krupp
The last quote was particularly striking given EDF's reputation as the ultimate insider in the environmental movement, and probably the green group with the closest ties to the Administration.
And Energy Action Coalition, the organizers of the upcoming Power Shift youth climate conference, showed that environmentalists weren't just cyber-angry; they were actually angry, announcing  that "thousands of young, forgotten Obama voters" were going to protest outside the White House on 18 April.