Dick Cheney is surely the most visible ex-vice president these days.
But Al Gore is almost certainly the most influential.
As Congress wrestles with politically explosive issues surrounding climate change and energy, Gore is simultaneously everywhere and nowhere.
He's worked the phones to squeak a bill through a key legislative committee. He's serving as an informal counsel to allies on Capitol Hill and inside the Obama administration, as they seek to solve a complicated political equation.
The not-for-profit Gore heads is running ads in targeted congressional districts, and holding town-hall meetings across the country to drum up support for climate-change legislation. The slideshow made famous in "An Inconvenient Truth" has now been shared more than 30,000 times and counting worldwide.
The one thing the former vice president is not doing very much of: talking in public about what he's doing behind the scenes.
"Gore is playing three levels of chess on this," said Chris Lehane, a former Gore aide and Democratic strategist. "He picks and chooses his places carefully. You're more powerful when you're shaping things from the outside, from a position of your own power."
Gore has been in the news recently in his role as chairman of Current TV, which employs two journalists who are now jailed and facing trial in North Korea. The former vice president has kept a low public profile on that issue, too, even amid speculation that the State Department would send Gore to the country to help negotiate the journalists' release.
And Gore is serving as a mostly invisible hand shaping the "cap-and-trade" bill now before Congress. The bill would impose a national limit on greenhouse gases and allow polluters to buy and sell emissions credits -- a step Gore and other environmental advocates argue is critical to addressing global warming.
Democrats credit Gore with putting environmental issues on the national agenda -- and, with one of Washington's thickest Rolodexes, making sure those issues stay there through a tortuous legislative route.
"He's been a prophet on this issue," said Rep. Edward Markey, D-Mass., a co-author of the cap-and-trade bill that was approved by the House Energy and Commerce Committee last month. "Al Gore adds a luster to an issue that's indispensable."
Gore aides and associates say the former vice president believes he can be more effective as a behind-the-scenes player, rather than as the public face of legislation, or with a formal role in the Obama administration.
Gore Feels He Can Best Act From Outside Government
With a Nobel Prize under his belt, and after being the subject of an Oscar-winning documentary, he feels he can best move the process along from the outside.
"His work is evident; he is not," said Daniel J. Weiss, a veteran environmental activist who serves as director of climate strategy at the Center for American Progress. "He's being very judicious about the use of the Gore brand. It shows that this for him is about solving the problem, and not about him."
The relatively low public profile also reflects a political reality that Gore himself is aware of, associates say: More than eight years after almost capturing the presidency, Al Gore remains a polarizing figure -- and an easy target for Republicans.
When Gore testified before Congress on the issue in April, Rep. Marsha Blackburn, R-Tenn., pressed him on his financial ties to Kleiner Perkins Caufield & Byers, a venture-capital firm that has invested heavily in green technologies.
"I think it's really important that no suspicion or shadow fall on the foremost advocates of climate-change legislation," Blackburn said. "So I wanted to give you the opportunity to kind of clear the air about your motives and maybe set the record straight."
Gore laughed -- and sighed -- before telling Blackburn that the money he's earned from Kleiner Perkins helps fund his not-for-profit group, the Alliance for Climate Protection.
"Congresswoman, if you're -- if you believe that the reason I have been working on this issue for 30 years is because of greed, you don't know me," Gore said. "I understand exactly what you're doing, congresswoman -- everybody here does."
Though the hearing marked his only major public appearance on behalf of the bill, Gore has been active in pressing the issue in Washington. Last month, with the climate-change bill facing a critical vote in the House Energy and Commerce Committee, Gore phoned a few wavering members -- both liberal and conservative Democrats -- directly.
Gore Called Congressmen Directly While Lobbying for Climate-Change Bill
Rep. Eliot Engel, D-N.Y., said it was the first time he'd had a lengthy, one-on-one conversation with the former vice president.
"What he said to me was he thought this bill was a monumental bill, of monumental importance," Engel said. "He likened this to the Civil Rights Bill of the '60s -- years later, generations would look back and remember who voted for it, and who didn't."
Engel said he was on the fence about the bill because he felt it didn't go far enough: too many concessions to industry, and not enough funding for flex-fuel vehicles, he thought. But he wound up voting yes.
"His discussion with me factored in greatly to the decision," Engel said. "I have such tremendous respect for him. Here's a guy who was really elected president and didn't get it. He could have been bitter, angry, could have retreated into seclusion, or made a lot of money. He chose instead to take up this issue."
Gore knows the congressional dynamics better than almost anyone. Before serving in the Senate and as vice president, he sat on the Energy and Commerce Committee for eight years as a member of the House, alongside a few members who are now powerful forces in Congress, including Markey and committee chairman Henry Waxman, D-Calif.
Gore's network of associates stretches deep into the Obama administration. He's in regular touch with Carol Browner, the assistant to the president for energy and climate change who served as EPA administrator in the Clinton administration, and as Gore's legislative director when he was a senator before that.
Since he knows the major players -- and so many of those players respect Gore's role -- the former vice president can be more effective from the outside than if he was actually serving in an official capacity, Weiss said.
"If he were working inside the administration, he'd be constrained by what he can say, what the priorities are," he said.
Gore's challenge will be to keep Congress' focus on environmental issues, even while the focus turns to what may be a bigger legislative fight over healthcare.
His grassroots network has paid organizers in 20 states and will continue to run ads targeting key House members on energy issues, aides say. Local coalitions organized by his not-for-profit -- representing business interests and labor unions, hunters and conservationists -- are prepared to keep the pressure on Congress.
"It's bringing a campaign mode to a legislative effort," Weiss said. "That's been hugely important and will get more important as we move through the legislative process."
Along the way, a man who's never been known as a first-rate communicator is getting his message across, Lehane said.
"He's leveraging the Gore brand, which when it comes to environmental and energy issues, it's the brand in the business," he said.