Ordinarily, a committee chairmanship is a wonderful feather in a Congressman’s cap, a sign of growing clout on Capitol Hill and an increased ability to deliver for the folks back home. It is also usually a harbinger of electoral invincibility.

When Rep. Richard Pombo (R-Calif.) became chairman of the Resources Committee at the start of the 108th Congress, at the tender age of 41, he had no reason to believe that the new job wouldn’t be a feather in his own signature cowboy hat.

Pombo is, after all, perfectly situated to come to the aid of the agricultural interests that dominate his district in California’s Central Valley. As chairman of the committee whose portfolio includes the energy industry, agribusiness and recreation, the former rancher is also certain to become a more potent fundraiser than ever before. Logic also dictates that he should become even more politically secure, after taking between 48 percent and 62 percent of the vote in his six successful campaigns.

But Democrats and the environmentalists with whom Pombo has tussled so frequently have other ideas. They argue that his new high-profile position will further highlight his views on the environment — which they characterize as extreme — and make him easier to challenge in future elections.

“He has a much bigger bullhorn, so the things he says, people will pay much more attention to,” said Scott Stoermer, communications director for the League of Conservation Voters.

Republicans scoff at the idea. And at this early stage of the cycle, not even Pombo’s most bitter foes are suggesting that the GOP-leaning district is about to fall into the competitive category just yet.

But one national Democratic operative called the district “one we’re going to watch.” And a California Democratic strategist envisions a four-year plan, in which a top-tier Democratic challenger holds Pombo to 52 percent or 54 percent of the vote in 2004, softening him up for defeat in 2006.

Just who that top-flight challenger might be remains a mystery. Democrats thought they had a good one last cycle in Elaine Dugger Shaw, a politically moderate lawyer and public school activist who came from the outer edges of the suburban East Bay, which had been added to the 11th district after redistricting.

Despite spending more than $316,000 of her own money and more than $595,000 overall, and despite competing in territory that was almost 40 percent new to Pombo and considered hospitable to moderates, Shaw lost by 20 points. Pombo spent close to $1.1 million on his victory.

Still, Shaw said she believes Pombo is beatable, and is considering running again.

“I do believe it makes him more vulnerable,” she said of Pombo’s chairmanship. “It will galvanize the environmental movement.”

Pombo is a leading Congressional critic of the Endangered Species Act. He has mocked many environmental regulations. And he went to the Supreme Court — unsuccessfully — to declare the Environmental Protection Agency’s American Heritage Rivers watershed protection program unconstitutional.

It is those types of actions, Pombo’s critics hope, that will eventually get him in trouble, especially with swing voters in his district, who are bountiful. The newly drawn district would have given President Bush an 8-point victory over Al Gore in 2000, and Republicans hold a 46 percent to 39 percent edge in voter registration.

“Pombo is even more extreme than most Republicans,” Stoermer said. “The folks in the middle who will matter most in that district will really be turned off.”

Still, no great moderate uprising has been evident in the 11th district, despite Democrats’ high hopes in the past decade of taking back turf that was once represented by House Democratic Whips Tony Coelho and John McFall.

Doug Heye, a spokesman for Pombo, said that contrary to his critics’ conclusions, the Congressman sees his chairmanship as a chance to moderate his image, to forge consensus on an array of controversial environmental measures.

“There are too many areas of agreement for us to get bogged down in partisan squabbles,” Pombo said last month when he was named Resources chairman.

Pombo’s defenders point to his appointment of Rep. Wayne Gilchrest (R-Md.), who is lauded by environmentalists for his record on clean water issues, as chairman of the subcommittee on fisheries conservation, wildlife and oceans, as a sign of Pombo’s flexibility.

“I don’t know what they’re talking about,” Heye said of the argument that his boss is now more vulnerable.

Heye accused environmental groups of reflexively opposing Pombo’s environmental initiatives — like his bill last year to ban the use of the gasoline additive MBTE — because it hurts their fundraising efforts to cooperate with him.

And while critics accuse Pombo of paying too much attention to the rural interests in the Valley portion of his district at the expense of the East Bay suburbanites, Pombo has previously served on the Transportation and Infrastructure Committee, where he could attend to issues like traffic congestion that are near and dear to suburban voters’ hearts.

“Electorally,” Heye said of his boss, “he’s feeling pretty comfortable.”