WASHINGTON -- Duane Alton opened the first Alton Tire Center in Liberty Lake, Wash., in 1964. Since then, he has built a dozen more stores near the Idaho border, along with a political creed that spurred him to give $750 to Stephen P. Laffey's 2006 Senate campaign.

"The people that earn the money should keep the money," Alton said in a telephone interview last week. They should enjoy "the fruits of their labor" with minimal taxation or interference from "the bureaucrats in Washington, D.C."

New York investment executive Leon J. Weil, a former U.S. ambassador to Nepal, said he thinks Sen. Lincoln D. Chafee "is probably a pretty darned good guy." But Weil said he gave $400 to Republican primary challenger Laffey because Chafee's record on taxes has been "counterproductive to the health of our economy."

Like hundreds of contributors nationwide, the tire retailer from outside Spokane and the financial executive from Manhattan's East Side are members of the Club for Growth who are bankrolling a little-known Rhode Island mayor's bid to topple an incumbent backed by the Bush White House and the national GOP.

No senator in Rhode Island history has faced a primary opponent as well-financed as Laffey. No Republican in the country is in greater danger of losing a Senate primary this year than Chafee.

The Club for Growth has been a key to Laffey's rise to the big leagues this election season, raising almost $705,000 for his campaign -- about 42 percent of his late-August total of nearly $1.7 million.

Two years ago, the 36,000-member Club for Growth -- which advocates federal tax cuts, free trade and smaller government -- helped President Bush in key swing states. The club also helped to defeat Senate Democratic Leader Tom Daschle of South Dakota.

While one branch of the club spurred its members to write checks to Laffey, another has spent several hundred thousand dollars to criticize Chafee --and sometimes ridicule him -- in television ads. In the past week alone, the Club for Growth has reported expenditures of more than $300,000 on TV advertising and related costs.

Sheila Krumholtz, acting chief of the Center for Responsive Politics, said groups such as the Club for Growth seek out "candidates who already share their ideology." But in a lawsuit filed last year, the Federal Election Commission has challenged the the club's status as a nonprofit entity that raises and spends large sums outside the FEC's regulatory reach.

Chafee has much deeper pockets than Laffey, a fact that the challenger has tried to exploit by presenting himself as the foe of "special interests" intent on protecting Chafee and the status quo in Washington.

But his reliance on the Washington-based Club for Growth raises the question of whether Laffey is beholden to a "special interest."

On the contrary, Laffey replied last week, the club is a "general interest" group because it favors tax cuts that would provide a general benefit to the public.

His defines "special interests" in the language of Washington and the FEC, as groups that use "political action committees" or PACs. But Laffey does not count himself as indebted to the Club for Growth's PAC because it has made no direct contributions to his campaign. Rather, it has aired the anti-Chafee ads, outside his legal control, Laffey said.

All the same, Laffey said he does not turn away special interest money from PACs. "I just don't get very much of it," Laffey said. The large majority of his PAC contributions, more than $23,000 so far, have come from groups that support the state of Israel.

He has accepted contributions from conservative PACs -- $5,000, for example, from the Washington-based Citizens United Political Victory Fund.

Several well-known conservatives have contributed to Laffey, including William F. Buckley Jr., a founder of the National Review, who gave $1,000.

Laffey has also received contributions from some individuals listed in his FEC reports as employees of anti-abortion groups. He did not directly answer the question of whether those constitute "special interest" contributions. Laffey describes himself as personally opposed to abortion but reconciled to court decisions that have made abortion rights a matter of "settled law." He supports certain limits on legal abortion that Chafee opposes.

Chafee has stepped up his counterattacks on the Club for Growth. During a televised debate with Laffey last month, he called it "one of the most nefarious and infamous of all special interest groups . . . the Goliath, the great white shark."

He added fresh accusations in an interview last week, saying that the group's anti-tax program is actually "their cover story" for a hidden social agenda of opposition to gay marriage, abortion and fetal stem-cell research.

Chafee said his evidence for the charge is "who they go after." He cited the club's support for U.S. Rep. Pat Toomey's 2004 primary challenge to Republican Sen. Arlen Specter of Pennsylvania. Toomey opposes abortion; Specter, who supports abortion rights, narrowly won the race.

"Maybe Senator Chafee could explain why the club supported Jim Kolbe over a social conservative," replied Toomey, a Rhode Island native who became president of the Club for Growth after he left Congress last year.

The club backed Representative Kolbe, a gay Republican from Arizona who supports abortion rights, when he drew a 2004 primary challenge from an anti-abortion conservative who opposes gay marriage.

"You will never find any reference to any social or cultural or, for that matter, foreign policy or defense issue" in the club's advertising, Web site or literature, Toomey said.

Toomey called Chafee's accusations "patently dishonest . . . just an age-old technique that politicians use to change the subject" away from their own public records. "It's a shame that Senator Chafee would stoop to do this."

Chafee suggested that the Club for Growth has flouted federal election laws.

"It seems to me they've broken just about every one I can think of," Chafee said. He revised that a moment later to "many laws" and began to list allegations in last year's FEC lawsuit.

In fact, the civil case has yet to be argued in federal court, so the Club for Growth has not been found in violation of any of the regulations cited in the lawsuit.

The lawsuit is part of a broader effort to restrain a type of political spending that mushroomed during the 2004 elections -- helping liberal as well as conservative causes. Election law analysts view the suit as something of a test case for reining in so-called "527s," independent groups that raised and spent hundreds of millions of dollars outside the FEC's regulation that year. The groups are named for the section of the tax code that controls such nonprofits.

Leading 527s on the right included the Club for Growth and Swift Boat Veterans for Truth; the left had MoveOn.org and Americans Coming Together. Some unions also spent money through 527s -- among them the Laborers and the Service Employees, both supporting Chafee this year.

Larry Noble, a Washington, D.C., expert on federal campaign finances said the FEC suit against the club is an effort "to set one clear line." If the FEC wins the lawsuit, all such groups "will have to take a look at that and say there's where the line is" that triggers FEC fundraising and spending restrictions.

To Duane Alton, the tire store owner, and Leon Weil, the New York executive, Chafee's view of their organization is a side issue. Such Club for Growth rank-and-filers said their main interest in Rhode Island's election is Chafee's approach to taxes and other economic policies.

"It's his record, and he has to pay for it," Weil said.

jmulligan@belo-dc.com / (202) 661-8423