THESE WERE THE FIRST real fighting words I'd heard from Mark or Tom. Both men know a lot about policy, and their voting records are stellar, but when I asked around, environmentalists spoke respectfully of the Udalls but singled out others—like Ed Markey, Henry Waxman, and Earl Blumenauer—as the real environmental leaders in Congress. This could be a matter of seniority—the three men have served a combined 75 years in the House. Or geography—Markey, Waxman, and Blumenauer represent big, liberal cities (Boston area; Los Angeles; Portland, Oregon) and don't have to accommodate the agriculture, mining, and drilling industries of New Mexico and Colorado.

Or maybe the Udalls just haven't hit their stride. With their nuanced positions and measured way of speaking, Mark and Tom sometimes come across as more wonkish than visionary. Mark's attempts at slogans—"Green is the new red, white, and blue!"—sound like recycled platitudes, while Tom seems too steady and fastidious for the daring frankness that might inspire a movement. When I pressed him about his achievements, he first mentioned his success preserving the Valle Vidal as well as the Valles Caldera, an 89,000-acre former ranch in the Jemez Mountains, but then shifted quickly into the minutiae of preventive health care and "finding creative ways to build the job base in my district."

Relieved though I was that folks in Gallup were getting their flu shots, I wanted a Udall who would fight. But the most pugilistic one, Randy, says he'll never run for office. "National energy policy has been stuck on stupid for a long time," he told me. "We've never been able to speak truth to power about energy. We're devouring the world. We're living like gods, and people think this is a normal state of affairs. Energy is warping our national policies, and it will for 40 years. If you get it wrong, you steer the nation into a ditch."

In Congress, however, tough talk doesn't always get you anywhere. Persistence may. Two months after our Culebra climb, Mark and Tom scored a big win. Their Renewable Electricity Standard bill, rewritten as the Udall-Platts Amendment by Republican Todd Platts of Pennsylvania, passed the House. "It's a major departure, and a signal that it's no longer business as usual," said Dave Alberswerth, senior policy adviser for the Wilderness Society. "And it would make an important down payment on stopping greenhouse gases."

Meanwhile, House Democrats passed a bill that would reform the Mining Law of 1872, and Mark Udall sponsored bills to block oil-shale leases on public land and to protect Colorado's Roan Plateau from drilling. But it seemed unlikely these bills would make it through the Senate.

Randy Udall's remark that climate policy would be determined by western senators had sounded like hyperbole until I watched what happened to the Renewable Electricity Standard in June. The top dogs on the Senate Committee on Energy and Natural Resources are both from New Mexico—Democrat Jeff Bingaman serves as chair and Pete Domenici is the ranking Republican. Bingaman introduced the RES; Domenici blocked it. Thus, the most significant step in decades toward ending American oil dependence rose and fell with the two gentlemen from New Mexico.

The weakened bill was blocked again when 39 Republicans and one Democrat, Mary Landrieu, objected to the end of oil subsidies. Only one vote shy of the 60 required to force a vote (one of the few Republican defectors was Gordon Smith), Democrats had an opportunity to show some bare-knuckled political courage by forcing the Republicans into an embarrassing pro–Big Oil filibuster or by twisting the arm of a single senator. Instead, in a move Mark Udall called "shortsighted, misguided, and beyond disappointing," Majority Leader Harry Reid stripped out the oil-subsidies ban as well as the renewable-energy standards, leaving a modest fuel-economy increase, a boon to corn-based ethanol, and a mandate to change your lightbulbs. The bill passed in December.

While even the greenest Senate may not be able to solve the climate crisis, 2008 could be a historic period of realignment. Four seats held by anticonservation Republicans are considered toss-ups. Green-leaning challengers are leading in Virginia and New Hampshire, and Tom and Mark were early favorites to replace Domenici and Wayne Allard, who are both retiring.

"If you turn Allard into a Udall and turn Domenici into a Udall," says Ned Farquhar, energy advocate for the Natural Resources Defense Council, "there's going to be a gigantic change in the West's influence, both on climate and on energy."

The Udalls see that. "[Mine] is a crucial race to generate a 56- or 57-vote majority in the Senate so that we can really grab the once-in-a-lifetime opportunity," Mark told the political blog MyDD.com in December. In the same interview series, Tom said part of his reason for running is "trying to push forward the things we wanted in 2006 that the president and the minority in the Senate have blocked."

While this brand of steady teamwork may not capture the same headlines as a self-styled maverick like Montana's Brian Schweitzer, it may be the bureaucratic slog, not the cowboy on a white horse, that wins the war. After all, Mo Udall's Alaska Lands Act bounced around committees for years before alignment between the House, Senate, and President Jimmy Carter allowed it to become law. This generation of Udalls are consensus-building policy whizzes who love the outdoors, and maybe that's precisely what we need.