The growing number of attacks by the conservative Club for Growth against moderate Republicans has had the side effect of swelling the campaign coffers of such centrist GOP groups as the Republican Main Street Partnership.

The Main Street group’s political action committee, which contributed to just one candidate in 2000, expects to spend $1.6 million this year on at least 21 moderate Republican candidates, said Sarah Chamberlain Resnick, executive director of RMSP.

In addition, the Main Street Individual Fund, a loosely affiliated so-called 527 group, has raised $3.5 million during this election cycle, according to Resnick. Such groups are largely unregulated political organizations registered under Section 527 of the Internal Revenue Code.

Resnick fingered the Club for Growth as the main reason for her group’s financial windfall. For the past three election cycles, the Club for Growth has spent millions of dollars to promote primary challenges by conservative Republicans against moderate GOP lawmakers.

“I hate to admit it, but it’s true,” said Resnick. “They’re just getting moderates in this country riled up. … Frankly, without Club for Growth, we wouldn’t need to raise this kind of money.”

The downside, she added, is that most of the Main Street money goes toward defending “good Republicans” from other Republicans, rather than trying to expand the playing field against Democrats.

The Club for Growth, which boasts 9,000 members, has targeted GOP moderates because they consider them big-government supporters who are weak-kneed on cutting spending on Medicare, Social Security and other social programs. Members of the club often say they are looking to purify the Republican Party and make it a party that takes a hard line on reducing the size of government.

But Rep. Tom Davis (R-Va.), an RMSP member, said the Club for Growth is just hiding a radical, anti-abortion agenda behind its demands for fiscal responsibility.

“Their primary endorsements are for pro-life candidates,” said Davis. “You need to pull the mask off the Lone Ranger and reveal the social agenda masquerading as fiscal conservatism.”

In 1999, Club for Growth organized itself as a 527 political group. In the 2000 election cycle, it gave nearly $4 million to conservative candidates to put the heat on moderate Republicans, said Club for Growth Executive Director David Keating. The club also has a closely affiliated PAC.

By contrast, in 2000, RMSP’s PAC was struggling to get off the ground. Its sole $5,000 contribution that year went to former Rep. Rick Lazio (R-N.Y.), who lost his Senate bid against Democrat Hillary Rodham Clinton.

In the 2002 cycle, the Club for Growth began targeting high-profile House moderates such as Sherwood Boehlert (R-N.Y.) and Wayne Gilchrest (R-Md.). In that cycle, the Republican Main Street Partnership saw its spending jump to $205,000, spread over 27 Congressional candidates, Resnick said.

This year, the $1.6 million which RMSP’s PAC expects to spend will go toward running ads and giving money to vulnerable incumbent moderates as well as moderate contenders for open-seat races, Resnick said.

Though the Main Street group has increased its take, its treasury still pales compared with the Club for Growth’s. The club spent more than $8 million in the 2002 election cycle, and in this cycle the group has already matched that amount as of early May, Keating said.

Part of the reason for the club’s bigger war chest, Resnick said, has to do with how the groups operate. The Club for Growth has enough staff to “bundle” individual contributions to candidates. The Main Street group does not, instead sending out letters to the nearly 15,000 members of its PAC, asking for contributions to be sent directly to the candidate’s campaign, Resnick said.

For example, RMSP members collectively sent $250,000 in contributions to Sen. Arlen Specter (R-Pa.) during his recent primary fight against conservative Rep. Pat Toomey, she said. Despite substantial Club for Growth support for Toomey, Specter ended up with a narrow victory.

Resnick added that candidates backed by RMSP have never lost to a Club for Growth candidate.

“We’ve beaten them nine times and tied them twice,” said Resnick. “They’ve never beaten one of our incumbents.”

But Keating disputed the notion that the RMSP has been more successful.

“We haven’t seen any evidence of their effectiveness,” said Keating. “If you back incumbents, you’re going to win 98 percent of the time anyway.”

The Club for Growth’s Web site says that its members helped candidates win 17 of 19 targeted races in 2002, as well as eight contested primaries. The club also takes credit for helping to elect 12 of the 33 House GOP freshmen in 2002.

In a couple of recent high-profile match-ups between RMSP and Club for Growth candidates, however, the outcome is murkier.

RMSP, for instance, prevailed in the Specter race — though Keating argued that given Toomey’s obstacles, including Specter’s support from President Bush and conservative Sen. Rick Santorum (R-Pa.), he “couldn’t come any closer to winnable, except for winning.”

In Nebraska’s 1st district race to succeed retiring moderate Rep. Doug Bereuter (R), neither the RMSP-backed Curt Bromm — the Speaker of Nebraska’s unicameral and nonpartisan Legislature — nor Nebraska Cattlemen executive Greg Ruehle, who received the club’s endorsement, won the May 11 GOP primary. Negative ads by both groups appear to have boosted Jeff Fortenberry, a previously little-known Lincoln City Council member.

Keating, however, still declared victory.

“The number one goal was to defeat Bromm,” said Keating. “Ruehle was definitely our first choice, but Fortenberry is acceptable.”

Resnick countered that the club’s actions have only made it easier for state Sen. Matt Connealy, a popular Democratic moderate, to win the general election.

“I’m told [Fortenberry] now is a C-minus, and [Connealy] is an A-plus. So we’ve got a problem,” said Resnick. “It sets it up for the Democrats to win.”

RMSP and the Club for Growth are still sorting through which races they will target this year. Resnick said that even with the expanded fundraising base, RMSP doesn’t have the luxury of helping out every moderate.

For example, RMSP hopes to be able to help the Senate campaign of Rep. George Nethercutt (R-Wash.), who is challenging Democratic Sen. Patty Murray. But the group’s ability to do so depends on whether the club zeroes in on other moderates in heated primary or general election races.

“I’d love to take that money and go into Washington state and help George Nethercutt win,” she said. “But we can’t do that.”