WASHINGTON – Newt Gingrich’s underdog pitch for the Republican presidential nomination hinges on the fact that he will never have as much campaign money as front-runner Mitt Romney.

That’s not to say he is content with scraping by.

“We’d always like to have more,” he told The Atlanta Journal-Constitution last week.

The former U.S. House Speaker is traveling to California on Monday in search of campaign-sustaining cash. The state will grant more convention delegates than any other in its June 5 primary, and Gingrich will have a smattering of public events, but the central purpose of the trip is to raise money: He will hold eight closed-door fundraisers in the span of three days, according to campaign spokesman R.C. Hammond.

In the interview Gingrich said he also has fundraisers planned in Texas, Tennessee and New York, and a trip to Georgia at week’s end will include fundraisers. Gingrich is attempting to build a nationwide campaign ahead of the crucial March 6 Super Tuesday contests, when Georgia and nine other states cast their votes.

But money follows momentum, and Gingrich has only one victory to his name – Jan. 21 in South Carolina. Meanwhile, a rival for the affections of the party’s conservative wing, former Pennsylvania Sen. Rick Santorum, reported raising $3 million in three days after winning a trio of contests last week.

Gingrich "can raise money between now and Super Tuesday but not a great deal of money,” said Fred Malek, a finance director for John McCain’s 2008 presidential campaign. “I think his fundraising will be eclipsed clearly by Romney and also by Santorum up until Super Tuesday, where it’s incumbent on him to win some more and demonstrate his viability.”

A key component of Gingrich’s money-seeking strategy involves courting supporters of Texas Gov. Rick Perry, who dropped out of the race before the South Carolina primary and threw his support behind Gingrich. Perry had a financial juggernaut in place to rival Romney's: In the third quarter of 2011 Perry raised $17.2 million, the most of anyone in the presidential field. Gingrich, by contrast, raised $12.7 million for the entire year.

Two Perry backers, Roy Bailey of Dallas and Jim Lee of Houston, last month tried to recruit fellow Perry donors to Gingrich in an email.

“We have spoken with his campaign manager, national finance director, and Speaker Gingrich himself,” they wrote. “They know that Team Perry did a great job and has lots of capable finance leaders. They really want us to join their efforts. There is plenty of room at the table, and they welcome all our help.”

Bailey and Lee organized a Feb. 3 conference call that Gingrich said included about 70 Perry backers. Hammond said the call and events that weekend in Las Vegas brought in $2 million in pledged donations.

“There are a lot of folks who when they look at their choices and see one candidate in the race who has led very large national projects … a lot of people come to the Gingrich campaign and decide we’re the best choice,” Gingrich said in the interview.

But it is unclear how many Perry donors Gingrich actually swayed. The Gingrich, Santorum and Romney campaigns did not provide names of Perry donors who joined their efforts.

Brint Ryan, a former Perry backer and CEO of Dallas tax services firm Ryan Inc., said he is staying out of the race.

“I’m currently uncommitted,” he wrote in an email. “I’m not sure if I will re-engage before the primary or not. I’m very disappointed that Rick Perry, the person with the best record and the strongest experience, was not successful."

Malek said most of Perry’s big “bundlers” – who actively gather donations from others on behalf of the campaign – are like Ryan.

“Perry bundlers would be quite impactful, but I’m not aware of too many of them that are actively bundling for Newt at this point,” Malek said. “Some are getting with Romney, none are getting with Santorum and a lot of them are sitting on the fence”

As with voters, Gingrich must compete with Santorum for donors who are eager to see a conservative alternative to Romney, the former governor of Massachusetts who is struggling to rally the GOP base. Gingrich argued that he is the one with staying power.

“I think Rick’s had a good period right here this week, but we have consistently done better than he had up until then,” Gingrich said. “And the fact is I think when people look at his record voting with big labor, consistently voting to raise the minimum wage, against right to work, I think they’ll begin to realize there are some limitations [to his conservative claims]. …

“I think once the initial headlines go past and when people start comparing the two, I have much bolder proposals and much bolder accomplishments.”

Santorum spokesman Hogan Gidley pointed to the fact that Santorum defeated Democratic incumbents in Pennsylvania, a task the Republican nominee will face in the fall. Santorum campaigned in Texas last week, but Gidley said he was not specifically targeting Perry donors during that trip.

“Rick has met with a lot of big fundraisers in the last few weeks and the past few days,” Gidley said. “We’ll see what comes out of it. You can’t raise $3 million in three days without doing something right. … It’s not a hard sell to make when you have the only conservative candidate in the race.”

And as Gingrich pointed out, the money race isn’t everything.

“We also proved back in the summer we could run a campaign remarkably inexpensively,” he said, referencing the time when his senior staff departed en masse and the indebted campaign was left for dead. “Both Santorum and I have gone through periods with virtually no money.”

The candidates’ efforts have been supplemented by Super PACs that can take in unlimited donations. Backed primarily by $11 million from the family of casino mogul Sheldon Adelson, Winning Our Future has maintained a media campaign on Gingrich’s behalf in key states. Romney-allied Restore Our Future -- having raised $30 million last year – is the dominant member of the species.

Wyoming investor Foster Friess has been the biggest contributor to Santorum’s Red White and Blue Fund, but he said another unnamed donor gave $1 million last week after Santorum’s victories in Missouri, Colorado and Minnesota.

"I don't think I'm going to be needed,” Friess told Bloomberg Television when asked if he would contribute any more. “I can go back to the golf course because the money is rolling in.”