As agency heads go, Secretary of Energy Steven Chu is coming off a good week.
A day after giving what agency insiders described as a "strong" speech discussing his bold, long-term goals on clean technology, Chu was named by the White House on Tuesday to be one of three administration officials to represent the United States at the international global warming negotiations in Cancun, Mexico.
But despite the positive headlines, there are some dark clouds on the horizon for the first Nobel Prize winner in a president's Cabinet since the 1970s.
With Republicans just weeks away from taking control of the House, Chu is facing political challenges unlike anything he has faced before. And as an agency head who is known as more of a thinker than a political animal, it remains to be seen whether Chu has the stomach for the coming funding battles, oversight hearings and pushback over his plans to advance energy research.
"From a technical standpoint, Chu knows more than anybody, but I think from a policy perspective and from a political perspective certainly he struggled more than some," said Frank Maisano, an energy specialist at Bracewell & Giuliani. "But I don't see any signs that he's being pushed out or moving or interested in leaving."
On Friday, DOE spokeswoman Stephanie Mueller reiterated comments she made last month to Greenwire that Chu "has no plans to leave while there is still work to be done."
Still, with the political pressure he is sure to face in the coming weeks and months, some insiders on and off Capitol Hill cannot help but play the old Washington parlor game of trying to pick who would come next if Chu decided to leave.
Among the potential successors is a trio of departing governors, with Michigan Gov. Jennifer Granholm (D) as the most likely pick among that group.
Known as an energy innovator during her eight years as Michigan's chief executive, Granholm has earned praise for helping to foster the development of battery production and for helping to guide the automotive industry through some of its toughest challenges. She is already close to Obama, having served on his 2008 transition team. She is also media savvy, charismatic and hails from a politically important Rust Belt state.
Two other lame-duck governors who both have energy credentials and are garnering some attention are two-term California Gov. Arnold Schwarzenegger (R) and Colorado Gov. Bill Ritter (D), who declined to run for a second term this year to spend more time with his family.
On Capitol Hill, there are several potential candidates with strong energy pedigrees who won't be around for the 112th Congress. That group includes North Dakota Sen. Byron Dorgan (D), who serves as one of the most senior members of the Senate Energy and Natural Resources Committee.
Asked last week about the possibility of one day moving over to the Department of Energy, Dorgan declined to comment.
"Those are all rumors and speculation, and I'm not going to comment on rumors and speculation," Dorgan said. "Secretary Chu is doing a fine job, and I hope he continues doing that job."
Dorgan said he is not thinking about his post-congressional career just yet.
"My last day is Jan. 2," he said. "There's still time" to pass important energy legislation.
"I wish we could end this session with a renewable electricity standard and also pass the electric vehicle deployment bill I authored with Sen. [Lamar] Alexander [R-Tenn.]. There's several things we should do on energy; we're just trying to determine whether we have the votes."
Outgoing Rep. Rick Boucher (D-Va.) is another potential candidate for a DOE opening. The 14-term congressman, who chaired a subcommittee on the Energy and Commerce Committee, is a savvy politician who is also highly respected for his technical expertise.
"As a former chair of the energy subcommittee, he not only knows probably as much as Chu on the technical aspect of it, but he understands politics and policy as well or better than anybody," Maisano said. "But is it something he wants to do? I don't know."
Boucher is a champion of coal power and has occasionally clashed with U.S. EPA over mining issues. And while those efforts may not endear him to some on the left, they may earn the congressman support across party lines.
One energy insider suggested last week that Boucher might be better-suited filling one of the several current agency leadership vacancies that have opened up under Chu, including undersecretary for Energy.
Other congressional names being mentioned include outgoing Sen. Blanche Lincoln (D-Ark.), who sits on the Energy and Natural Resources Committee but who is viewed as more of an agriculture expert. Meanwhile Senate Energy and Natural Resources Chairman Jeff Bingaman (D-N.M.) suddenly became an intriguing possibility last week when he suggested that he had not ruled out retirement rather than running for a sixth term in 2012.
Of course, there is nothing to say that the White House won't again look outside the ranks of elected officials if it had to find a replacement for Chu. John Rowe is chairman and CEO of Exelon Corp., one of the nation's largest electric utilities. In that role Rowe oversees one of the largest fleets of nuclear power plants in the country. Exelon also happens to be based in Obama's hometown of Chicago.
Still, all the speculation over who might come after Chu will remain just that until it becomes any clearer that a vacancy may come up.
"Steven Chu has been one of the most forceful intelligent secretaries of Energy, and he's got a lot of objectives to achieve," said Daniel Weiss, a senior fellow and director of climate strategy at the Center for American Progress Action Fund. "I don't think he'll be peddling home to California anytime soon."