Former Los Angeles Mayor Richard Riordan endorsed fellow Republican Kevin James for mayor Friday. But how much can he help the fledgling candidate?

Riordan, who served from 1993 until 1999, remains popular among white conservative voters in the city, many of whom reside in the Western San Fernando Valley.  They are also high propensity voters. They’d cast ballots for dogcatcher, if L.A. had one.   Will they listen to Riordan?

In a statement, Riordan praised James as “the only candidate capable of creating real pension reform for the City of Los Angeles.”

“His complete independence from the special interest groups at City Hall will allow Kevin to establish real change for L.A.,” the millionaire businessman and former mayor said.

James, an entertainment attorney and former radio talk show host, has had a difficult time gaining traction in the race.  He placed fourth in a recent KABC poll, with 12% support. He would have to at least double that showing on election day to approach the runoff.

The first-time candidate also has raised just $330,000, a fraction of the three candidates ahead of him: L.A. City Controller Wendy Greuel ($3.6 million), and City Council members Eric Garcetti ($3.7 million) and Jan Perry ($1.5 million).

At the same time, James is getting a big assist from the Better Way LA Political Action Committee, headed by Republican advertising specialist Fred Davis. Thanks to $600,000 from Dallas billionaire and GOP stalwart Harold Simmons, the group launched TV ads for James on Friday (see above).

James is the only Republican in the group of top candidates, which might help, even though the race is officially non-partisan. But just 16.3% of L.A. city voters are registered Republicans. GOP voters will likely comprise a larger percentage of those who cast ballots in the March 5 primary.  Greuel and Perry are going after them too.

James has said his opponents, as elected officials, are part of the problem. He says it’ll take an outsider like him to turn the city around. The argument is not unlike Riordan’s in 1993, when he said he was the only one “tough enough to turn L.A. around” after the riots sparked by the Rodney King verdict.

Endorsements can give credibility to a lesser-known candidate like James. But it's unclear whether Riordan fans rally to James, whose roots run much shallower in L.A. civic life.

“I am honored to have the trust and support of Mayor Richard Riordan,” James said in a statement Friday. Later, in an e-mail to supporters, he sought to turn the endorsement into money: “Can you chip in and donate $25, $50, $100 or $250 today?”