A conservative group that champions tax cuts and limited government did something yesterday it has never done before: It endorsed a Democrat.

Rep. Henry Cuellar of Texas is the first Democrat to receive an endorsement from the Club for Growth, which champions free trade, school choice and other issues dear to many Republicans.

Cuellar faces former Rep. Ciro Rodriguez in a March 7 Democratic primary. In 2004, Cuellar beat Rodriguez by 58 votes after a prolonged legal battle. Cuellar then attracted 59 percent of the vote in the general election.

“This is a guy with guts and commitment to the principles he believes in,” the Club’s president, Pat Toomey, said of Cuellar in a conference call with reporters.

Toomey cited Cuellar’s support for the Central America Free Trade Agreement, repealing the estate tax and reforming the public-school system as reasons for the Club’s endorsement.

He added that the endorsement should make it loud and clear that the conservative group, which claims more than 30,000 members nationwide, is above the partisan fray.

“By endorsing Representative Cuellar in this primary, we are demonstrating what we have always maintained … and that is that we’re committed to a set of ideas,” said Toomey, a former Republican congressman from Pennsylvania. “We’re not committed to a party. We’re not part of a party.”

Rodriguez’s campaign manager, Oscar Sanchez, said voters in the 28th District, stretching from San Antonio to the Mexican line, deserve to know who is backing Cuellar. “We’ll definitely be using it in campaign literature,” Sanchez said of the Club’s backing.

He lashed out at the Club’s support for tax cuts for the wealthy and the partial privatization of Social Security spearheaded by President Bush and other leading Republicans last year.

Toomey said he was unconcerned about Cuellar’s Democratic opponent’s using the Club’s endorsement against him in a district that leans slightly Republican, although he said he does not know if the congressman will be touting his new support in campaign brochures, on television advertisements or in speeches, as other candidates have done.

A spokeswoman for Cuellar did not return phone calls seeking comment.

Bush won the district in 2004 with 53 percent of the vote but narrowly lost it in 2000, when Al Gore edged out the then-Texas governor. No Republican is seeking to win Cuellar’s seat.

The primary benefit of a Club endorsement appears to be money. While congressional candidates have until the end of the month to file their fourth-quarter fundraising returns with the Federal Election Commission, Toomey said yesterday that Club-backed candidates look to be faring well.

Cuellar is the eighth candidate this cycle to be endorsed by the Club, with the group playing a more aggressive role this cycle than in 2004. All but one of those candidates is seeking a House seat. In Rhode Island, the Club is backing Cranston Mayor Stephen Laffey, challenging Sen. Lincoln Chafee in a Republican primary.

Former state Rep. Tim Walberg, whom the Club is backing in a GOP primary with Rep. Joe Schwarz in Michigan’s 7th District, said earlier this week that he had raised $150,000 in one month of campaigning. Walberg attributed much of his fundraising success to the Club, which helps steer tens of thousands of dollars into candidates’ coffers by recommending them to its members.

Toomey said it is likely the Club will be endorsing more candidates in the coming months, or possibly sooner, but he declined to identify any possible contenders. The former congressman was himself endorsed by the Club when he ran unsuccessfully against Sen. Arlen Specter (R-Pa.) in the 2004 Republican primary.

There are spirited Republican Senate primaries in Nebraska and Tennessee, and many conservatives would like to see a Republican challenge centrist Sen. Mike DeWine in Ohio’s primary. Also, there are competitive GOP House primaries in California, Iowa, Illinois, Minnesota, Wisconsin and elsewhere.

The Club, so far, has only endorsed candidates in primaries.

“The Club has never endorsed eight candidates in an election year before,” Toomey said, “so we’re well ahead of where we’ve been.” Given that the Club raised a lot of money itself in 2005, he said, “we would be inclined to get involved in more races rather than fewer.”

The Hill reported this summer that several of Cuellar’s Democratic colleagues are not supporting the freshman’s reelection bid.

Democratic Reps. Charles Rangel (N.Y.), Luis Gutierrez (Ill.) and Ted Strickland (Ohio) contributed to Rodriguez’s campaign in the first half of last year, and at least eight more members attended a July fundraiser for Rodriguez held in Washington.