Just one month before Los Angeles’ nonpartisan mayoral primary, only a few Members of the city’s Congressional delegation have taken sides in the volatile and wide-open contest.

Nor is there much evidence that the mayoral candidates are aggressively courting L.A.’s House Members — with one exception.

That would be Rep. Maxine Waters (D), whose endorsement of now-Mayor James Hahn was thought to be pivotal in the 2001 open-seat race, and who remains undecided this time around. Waters has been described as the most influential uncommitted black leader in the city aside from basketball great Magic Johnson.

“Of all the people whose endorsements matter the least, I think it would be Members of Congress — except for Maxine’s, and hers would matter a lot,” said Raphael Sonenshein, a Cal State Fullerton political scientist and frequent radio commentator.

California political handicapper Allan Hoffenblum, publisher of the California Target Book, said that most Members of Congress in the L.A. megalopolis are fairly obscure and carry relatively little political clout on local politics.

“They get very little coverage in the L.A. Times” and other media outlets, Hoffenblum said. “Howard Hughes wasted a lot of money in search of anonymity. All he had to do was become part of the L.A. Congressional delegation.”

Not that the five major candidates for mayor haven’t touted Congressional endorsements when they get them.

The March 8 race features Hahn, state Sen. Richard Alarcon (D), former California Assembly Speaker Bob Hertzberg (D), City Councilman and former Police Chief Bernard Parks, and Councilman Antonio Villaraigosa, who lost to Hahn in the 2001 runoff.

If no candidate gets 50 percent of the vote in the free-for-all nonpartisan primary then the top two finishers will advance to a May 17 runoff.

Hahn is favored to make it into the runoff, unless he is sidetracked by a federal “pay to play” probe investigating whether city contracts were doled out based on contributions to the mayor’s campaign. So far, the case has ensnared some of Hahn’s allies but not the mayor himself.

“The big wild card in this race is what happens to the investigation,” said Howard Fine, a political reporter with The Los Angeles Business Journal.

Villaraigosa, who finished first in the 2001 primary only to lose the runoff to Hahn, is considered the next-strongest candidate. But Hertzberg has just begun a major advertising push, and Parks, who was thought to be fading, posted stronger-than-expected fundraising numbers last week, suggesting that his candidacy may not be doomed after all.

For Members of Congress, endorsing a candidate for mayor entails several risks.

For starters, the five leading contenders, though officially nonpartisan on the ballot, are all Democrats. So are the nine House Members and two Senators who represent the city. The Los Angeles County Democratic Committee recently decided to remain neutral in the race after endorsing Villaraigosa four years ago. Many Democratic officials are following their lead.

“They’re all good Democrats — and good friends,” said David Sandretti, a spokesman for Sen. Barbara Boxer (D-Calif.).

What’s more, organized labor is split in the race, with Hahn and Villaraigosa receiving significant support. And in a city as polyglot as Los Angeles, appearing to favor one ethnic group over another can be problematic.

“It’s nothing but trouble to stick your nose into a race where you have five Democrats, three largely supported by labor, two Latinos [Villaraigosa and Alarcon], one African-American [Parks], one Jew [Hertzberg] and one white [Hahn],” Sonenshein said.

Still, that hasn’t prevented at least a few Members from taking sides.

Hahn has been endorsed by Sen. Dianne Feinstein (D) and Rep. Grace Napolitano (D), who chairs the Congressional Hispanic Caucus.

Napolitano — who called the mayor “a true public servant, not a politician” — does not represent any of the city of Los Angeles, but she does represent several heavily Latino neighborhoods on the city’s edge. Her decision to shun Villaraigosa, the leading Hispanic candidate, is seen as a prime example of the political schisms that crisscross Los Angeles’ Latino community like earthquake faults.

Rep. Xavier Becerra (D), for example, was once a colleague of Villaraigosa’s in the state Assembly, but Becerra ran unsuccessfully for mayor in 2001, and the two have had a strained relationship ever since. Villaraigosa even contemplated running for Becerra’s House seat in 2002.

Meanwhile, two of the city’s senior Jewish House Members, Reps. Henry Waxman (D) and Howard Berman (D), endorsed Villaraigosa early.

“I didn’t endorse four years ago, but felt I had to for this race,” Berman said during a news conference last fall, according to an account in the Los Angeles Daily News. “When I look around and see all that needs to be done, I think we need a man of Antonio’s talents and beliefs.”

Hoffenblum said the two liberal Members endorsed Villaraigosa in part because he is the most liberal candidate in the mayoral race. But Berman may also be seeking an element of political protection: 56 percent of his district’s population is Hispanic. That figure was higher before the last round of redistricting, and some Latino leaders were angered when mapmakers — working off a plan crafted by Berman’s brother, a political consultant — protected white incumbents instead of creating more favorable districts for minority candidates.

Berman and Waxman once controlled a small political machine on the city’s west side, but its influence on local elections has waned in recent years.

The same can’t be said of Waters, however. She puts together political slates every election, which candidates pay to be included on, and mails the list to tens of thousands of black voters. Her stance on the mayor’s race is the subject of much speculation.

Waters endorsed Hahn over Villaraigosa in 2001, angering Latinos and some liberals who were hoping that a rainbow coalition of support could propel Villaraigosa into the mayor’s office. But many black leaders, like Waters, sided with Hahn in part because his father, a 40-year Los Angeles County supervisor, was a beloved figure in the black community.

Yet Hahn angered Waters and many black voters shortly after taking office by firing Parks as police chief.

“The mayor, whom I strongly supported, has failed to be fair to the African-American community,” an outraged Waters wrote in an opinion piece.

This tension hasn’t necessarily aided Parks, who would be the likeliest beneficiary. Many analysts believe that Waters’ reluctance to endorse Parks in this year’s mayor’s race — and a similar neutrality by Magic Johnson, who has a record of endorsing local candidates for office — speaks volumes about the state of his campaign.

“I do believe she’ll commit before the primary, but I have no comment on her timetable or thinking at this point,” Mikael Moore, Waters’ spokesman, said Monday.

To be sure, Waters’ endorsements aren’t always golden, even in adjacent districts. In the 2001 special election to fill the seat vacated by the late Rep. Julian Dixon (D-Calif.), Waters backed an ambitious young state Senator over the ultimate winner, Diane Watson, who had just finished a stint as ambassador to Micronesia.

But months later she redeemed herself by backing Hahn and the winner in the hotly contested runoff for city attorney.

In the meantime, there is at least one endorsement from a white politician that would trump Waters’ — the backing of California Gov. Arnold Schwarzenegger (R). If the governor gets behind anyone, it is likely to be Hertzberg, a centrist and informal adviser who served on Schwarzenegger’s transition team in 2003.

Last week Schwarzenegger said that he would wait until the runoff before deciding whether to get involved.