Jim Martin, the conservation director for the largest fishing tackle company in the United States, is a registered Republican who, like many sportsmen, had high hopes when President Bush took office. But he now eyes the administration more warily, worried about its push for oil and gas development on public land and its position on global climate change.

"They should not assume because we're registered Republicans we'll vote for Bush," said Martin, who works for Pure Fishing. But he added that Democrat John F. Kerry still has to prove he deserves the loyalty of hunters and fishermen. "Neither side should assume they have this vote wrapped up," Martin said.

In the next few weeks, the Bush and Kerry camps will be rolling out their campaigns to win over what is often called the "hook and bullet" crowd. Numbering about 50 million strong and living in swing states such as Pennsylvania, Ohio, West Virginia and Arkansas, the men and women who hunt and fish in this country have become significant players in the presidential campaign.

These voters are attractive for a number of reasons. They tend to be politically active; 93 percent of registered hunters voted in the 2000 presidential election, according to a Congressional Sportsmen's Foundation survey conducted by Roper Starch Worldwide, well above the national average. Although they lean Republican -- 46 percent, according to the CSF -- nearly a third are independent and 18 percent are Democratic, leaving ample room for political appeals.

"This is not a monolithic community," said Chris Wood, vice president for conservation at Trout Unlimited.

Before the Democratic primaries, Kerry displayed his hunting credentials by shooting two pheasants in Story County, Iowa, with just two shots. Bush has wooed conservation group leaders at his Crawford, Tex., ranch and at the White House over the past six months.

The number of American sporting and fishing enthusiasts has declined slightly over the past decade: A U.S. Fish and Wildlife Service survey reported hunters' numbers dropped from 14 million in 1991 to 13 million in 2001, with fishing aficionados declining from 35.5 million in 1991 to 34.5 million a decade later. But they constitute a huge voting bloc that often judges candidates on sportsmen's issues, and as consumers spent $70 billion in 2001.

In 2000, according to most accounts, hunting advocates judged Bush and Democratic nominee Al Gore primarily on their gun control stands. Seventy-eight percent of hunters surveyed by Roper Starch said gun control issues were "much" or "somewhat" more important to them in 2000 than in previous elections.

To Wayne LaPierre, executive vice president of the National Rifle Association, sportsmen and sportswomen have an easy choice this fall. The NRA has given Kerry a congressional scorecard rating of F since 1984, and LaPierre said he views the senator from Massachusetts "as the quintessential two-faced candidate. He votes one way, and now that he's running for president, he says he's another."

The Kerry camp takes issue with this assessment. The fact that Kerry has hunted for years sends a powerful message to voters that "this is not a typical national Democrat you see at the top of the ticket," Kerry regional director Jonathan Epstein said.

"Since he was a kid, John Kerry has hunted. He's owned guns," Epstein said. "It's a group he's going to fight incredibly hard for once he gets to the White House."

Still, gun rights groups are backing the Bush administration. As Merle Shepard, the Safari Club International's head of government affairs, put it, "They're easy to access." The administration's decision to allow hunting on about 50 wildlife refuges, for example, pleased Shepard and others.

The battle over conservation is more complicated. Many hunting and fishing advocates have criticized the administration for its treatment of wildlife habitat, whether it involves drilling for oil and gas near wildlife migration corridors or the prospect of easing regulation on public wetlands.

Paul Hansen, executive director of the conservationist Izaak Walton League, said although outdoors enthusiasts have been pleased with the administration's rhetoric, "on the ground, we've not seen the actions that support the words."

After a 2001 Supreme Court ruling questioned whether the Clean Water Act's jurisdiction extended to isolated wetlands often known as "ephemeral washes or streams," for example, administration officials briefly considered rules that would have made it easier to fill in these areas with commercial development. But the move sparked an uproar among "hook and bullet" groups in late 2003, and top officials dismissed the plan.

Since then Bush has pledged not only to protect 1 million acres of the nation's wetlands from development but also to add 1 million acres over the next five years and improve an additional million acres. Bush also approved hefty conservation funding as part of a recent farm bill.

James L. Connaughton, who chairs the White House Council on Environmental Quality, said the administration has been "more successful than any previous administration" in protecting wetlands. James D. Range, board chairman of the Theodore Roosevelt Conservation Partnership, who met with Bush in the Oval Office, said the president "has a real interest in our community. . . . It's something you can tell he both enjoys and cares about."

"The sportsmen who will vote firearms first will vote for Bush," Hansen said. "The sportsmen who will vote conservation first will have a tougher choice."

John F. Kerry's campaign stresses that he is a longtime hunter, and that he is not the "typical national Democrat you see at the top of the ticket."Some groups have announced their support for President Bush, but a fishing organization spokesman cautions: "This is not a monolithic community."