After the Republican House and Senate victories of 1994, environmental groups, and their allies in Congress and the White House, were forced to fight a desperate rear-guard action to protect core legislation, including the Clean Water Act and Clean Air Act. Real progress on issues like gas-mileage standards and the development of alternative fuels was next to impossible. “We got slam-dunked on almost every issue,” as Kathleen McGinty, former head of the White House Council on Environmental Quality, recalls; “and not just by Republicans but by Democrats as well.” She and other former aides give Gore high marks for steadfastness in the face of massive resistance. But the resistance came not only from the business lobby and their allies in Congress but also from some of the administration’s own top officials. As Gore himself recalls: “It was seen as an arcane, hobbyhorse issue: We’ll indulge Vice President Gore, and let him do his thing yet again, and then we’ll get back to what we know is the serious stuff.”

This internal clash came to a head in 1997, with negotiations over the Kyoto protocol on greenhouse-gas emissions, which the business community, and above all the energy industry, vehemently opposed. Timothy Wirth, a committed environmentalist and then under secretary of state for global affairs, assembled a bipartisan advisory group of a dozen or so senators to build support for the treaty. “I could not get a single White House official to come to any of these meetings,” Wirth recalls. “They would not identify themselves with Kyoto.” Wirth planned to assemble a range of such groups, as he had with earlier pacts; but the White House took over the process before he could do so and made no outreach effort. “It was a goddamn scandal,” Wirth says. “It was horrible.” Wirth stepped down a few weeks before the treaty was to be finalized.

Gore was quite taken aback when I relayed Wirth’s remarks. “He’s not talking about me,” he said. “I don’t know who he’s talking about.” But he also adds: “If I had been president, would I have bent every part of the administration and every part of the White House to support this? Yes, I would have. Does that translate into criticism of President Clinton for not doing this? No. I was vice president, not president.” Or maybe Gore would rather not do the translation. When the international negotiations looked as if they were about to collapse, in part owing to American resistance, Gore suggested that he fly to Kyoto to demonstrate Washington’s commitment. David Sandalow, who worked on environmental affairs at the National Security Council, recalls a meeting with a dozen advisers “in which nobody recommended he go, with the range of opinion running from neutral to strongly against.” Gore went anyway. “His arrival was galvanizing,” Sandalow says. (Others are less convinced.) Gore returned in triumph — and instantly encountered, he recalls, “resistance in the White House to even signing it, much less submitting it to the Senate for ratification.” Gore used his last dram of political capital to persuade Clinton to sign the Kyoto pact; it was never sent to the Senate, where it surely would have died an ugly death. The Clinton administration thus surrendered without firing a shot. For Gore, it was a humiliating denouement.

Gore’s advisers in the 2000 campaign worried that he would commit political suicide by global warming. The issue had advanced far enough in public consciousness that George W. Bush saw fit to endorse regulating carbon emissions (a position he promptly ignored once taking office). But it was still a net loser. Gore says he believes that he lost West Virginia, and possibly Kentucky, by calling for restrictions on coal-fired utilities. Gore could be excused a case of epic bitterness; but his total immersion in a cause he deeply believes in appears to have seen him through. The only what-if in which he indulged during our time together was to say, only half-jokingly, that if he had had the “presentation skills” he has since learned, “I think I’d be in my second term as president.”

Ah, the presidency. There are Web sites, and even a political action committee, dedicated to promoting a Gore candidacy. James Carville, the Democratic strategist, told Rolling Stone flatly, “He’s going to run, and he’s going to be formidable.” Several of Gore’s aides from the 2000 race are said to have assembled a shadow campaign team should Gore change his mind. But the people closest to Gore say, as one, that he does not so much as raise the subject. “Al knows where the sirens are,” says Roy Neel, who has been with Gore since the early days in Congress, “and he knows when it’s not real.” He adds that Gore “has rejected offers to do any sort of planning.” He has not, however, stopped others from planning on his behalf.

When I asked Gore why he hasn’t dismissed all the speculation by issuing a Shermanesque refusal to stand, as he did in 2002, Gore said, “Having spent 30 years as part of the political dialogue, I don’t know why a 600-day campaign is taken as a given, and why people who aren’t in it 600 days out for the convenience of whatever brokers want to close the door and narrow the field and say, ‘This is it, now let’s place your bets’ — If they want to do that, fine. I don’t have to play that game.” This sounded a lot like “I can get in late.” (Indeed, the buzz among the former aides is that Gore could jump in at the end of 2007 should the current contenders show significant weakness.) A few moments later, he said: “I’m not issuing a Shermanesque statement because that’s not where I am. I’m not ruling it out for all time. Although I cannot presently foresee any circumstances, such circumstances could emerge.”

“And such circumstances could emerge in 2008?”

“It’s extremely unlikely, but not impossible.”

In James Hansen’s view, which Gore shares, we have no more than 10 years to level off the production of greenhouse gases; by 2050, despite massive growth in population and the world economy, we must have cut global emissions to “a fraction of what they are now.” Otherwise, we go over the cliff. This is what Gore means when he says that the outer edge of the politically possible falls short of the inner edge of the necessary; and this is why he believes that the only hope is to transform the definition of the possible through a campaign of mass persuasion. There are now half a dozen greenhouse-gas bills in Congress; the most drastic of them would meet Hansen’s target through a combination of tough gas-mileage standards, requirements that utilities resort to alternative fuels and a market-based “cap and trade” system. Under such a regime, mandated by the Kyoto Protocol and now in place in Europe, companies receive an annual “allotment” of carbon emissions; those that produce even less can sell their “credits” to those who can’t or won’t make it under the bar. Of course this system works only if the annual “cap” starts low and gets smaller and smaller every year. Gore’s great fear is that business lobbies and lawmakers will unite around some kind of compromise legislation that will demonstrate “commitment” without actually driving up the cost, or driving down the permissible volume, of carbon emissions. And he views even the most stringent legislation as inadequate.