Scott Walker, governor of Wisconsin, speaks at the American Action Forum on Jan. 30. (Andrew Harrer/Bloomberg)

It was not yet 8 a.m. on a recent Sunday morning, but a crowd of heavyweight GOP donors was gathered on the back patio of Carl and Jimmy Westcott’s desert vacation home to hear from Scott Walker.

The eager reception for the Wisconsin governor and likely presidential candidate — who picked up a $100,000 check on the spot from one person at the Indian Wells, Calif., event — was repeated as he hopscotched across the country last week in the first fundraising tour for his new political committee.

In the intense jockeying to win the 2016 money primary, former Florida governor Jeb Bush and New Jersey Gov. Chris Christie are moving aggressively to lock down financial backers nationwide. On their heels is Walker, who has a 50-state network of wealthy contributors and small donors far more expansive than might be expected for a Midwestern governor and former Milwaukee county executive.

Walker’s thick donor file is the byproduct of a contentious effort to recall the governor in 2012 after he pushed through a law curtailing collective-bargaining rights for many public employees.

Fighting the unions became a national cause on the right. Rich conservatives rallied to Walker’s side, including influential donors who are part of a network organized by billionaire industrialists Charles and David Koch. Among his top supporters were the DeVos family of Michigan, casino magnate Sheldon Adelson and millionaire investor Foster Friess.

Since surviving the recall attempt, Walker has assiduously maintained his relationships with an expanding roster of top party fundraisers and financiers, courting them with regular phone calls, chummy visits and invitations to his inauguration last month.

“The recall provided him with a really interesting opportunity, because he made so many connections nationally with so many donors,” said Chart Westcott, a Dallas-based hedge fund executive, who introduced Walker at the breakfast fundraiser held last month at his parents’ home in Indian Wells. “He already has this base of people who have given him six figures in the past. Not a lot of the other candidates have a national network like that.”

In all, Walker raised almost $83 million for his three statewide races in the past four years — an eye-popping sum for a governor of a modest-size Midwestern state. Of the nearly 300,000 people who gave to his campaigns, three out of four donated $75 or less, according to people familiar with the figures.

“He has a mammoth small-donor list,” rivaled only by libertarian-leaning Sen. Rand Paul (Ky.), said Ron Weiser, a former finance chairman of the Republican National Committee.

Walker’s extensive fundraising network could help him pull in the kind of money that has eluded past Midwestern candidates such as then-Minnesota Gov. Tim Pawlenty (R), who ended his presidential bid in 2011 partly because of worries that he could not raise enough.

“It’s a tremendous political asset and strength for him,” Pawlenty said in an interview this week. “He has something I didn’t have. Because of the recall and his good work in Wisconsin, he’s got one of the largest direct-mail and Internet donor bases in the country and very established relationships with major donors. That’s going to allow him to raise a competitive amount of money to ride out the inevitable highs and lows of the campaign.”

Some party strategists noted that much of the money Walker raised was donated when he was the cause celebre in conservative circles — not a potential candidate vying against other prominent Republicans. But Walker aides contend that he can hold his own in the fundraising race, saying he is tireless about working the phones to reach potential donors.

“We are not ceding that ground to anyone,” said one top Walker adviser, who spoke on the condition of anonymity to discuss internal strategy.

His strategists don’t view the fundraising competition among the many 2016 hopefuls as a zero-sum game. Their pitch to contributors: I don’t have to be your first choice, but keep me on your radar.

During fundraising stops last week in Indian Wells, San Francisco, Denver, Nashville and Lakewood, N.J., Walker began cultivating supporters at small gatherings arranged by donors who have backed his past campaigns.

Nashville venture capitalist Andy Miller, who arranged a small breakfast for Walker, got to know him when he co-hosted a lunch fundraiser on Walker’s behalf during the recall fight.

“He just struck me as one of the most genuine men I’ve ever met in politics, and I’ve met lots of them, so I know that’s not always what you find,” said Miller, who added, “He’s my guy, 100 percent.”

Miller said he was amazed by how quickly Walker was embraced by potential donors who met with him at a Nashville restaurant. “People who told me things like, ‘I am not sure I want to make a decision that early,’ they came out of it, saying, ‘Wow, he’s it,’ ” Miller said.

Walker also has the support of Stanley Hubbard, a conservative billionaire who oversees a Minnesota broadcasting company.

“I love Chris Christie. I think Jeb Bush is a wonderful person. But right now, my family and I are backing Governor Walker,” said Hubbard, who also met the Wisconsin governor through the recall fight. “I think he would be a hell of a president because he has been there and done that in a very liberal state.”

Last week, Hubbard sent a check for $25,000 to Walker’s new political committee, Our American Revival. “And we will do more,” he said.

The political committee — which is being run by Rick Wiley, a former Republican National Committee political director — was set up under a section of the tax code that allows it to accept unlimited personal, corporate and PAC donations. The group is seeking to raise enough money to finance Walker’s travel and pay for a staff, but Walker is not expected to make a big fundraising push until later in the year.

Right now, his focus is on strengthening his ties to the big donors whose backing will be essential to financing a 2016 bid. GOP strategists say the top candidates will need to bring in at least $75 million just to get through the first three primary states.

The night before his Indian Wells fundraiser, Walker was a featured speaker at a private donor seminar put on by the Koch-backed political network at a luxury resort in Rancho Mirage, Calif. Standing on an expansive lawn festooned with twinkling lights, Walker touted his accomplishments as guests dined on filet mignon.

The Wisconsin governor, who has attended the seminars since 2011, is widely admired by the group for his efforts to curb union power and for prevailing in the hard-fought recall effort and last year’s reelection campaign, according to people familiar with internal discussions.

Still, few in the organization have settled on a candidate for 2016, and officials are just beginning to assess whether the network should jump into the primary fight.

“They have a deep reservoir of goodwill and respect for him, but most of them have not yet decided that he is the best alternative for president,” said one person with knowledge of donor attitudes.

Walker also has been a regular participant in the Republican Governors Association’s Executive Roundtable program, which allows wealthy contributors to mingle with GOP governors at quarterly policy seminars.

“He is extremely well received because he comes across in kind of a low-key, next-door-neighbor type of way,” said Fred Malek, a longtime party fundraiser who serves as the RGA’s finance chairman. “He’s not officious.”

While other GOP governors such as Christie, Rick Perry of Texas and Bobby Jindal of Louisiana also will lobby RGA donors, Malek said Walker also has a good shot at finding financial backers among the group’s 600 members.

“There is no question in my mind,” he said, “that he will have the resources to compete for the nomination.”