Fredreka Schouten and Christopher Schnaars

USA TODAY

WASHINGTON — Thousands of wealthy donors who helped fuel Republicans’ presidential ambitions in the last two election cycles have not donated to Donald Trump’s campaign or to other committees supporting his bid, underscoring the challenge the real-estate magnate faces in securing the hundreds of millions he needs to finance his general-election campaign.

Just 29 people who contributed to a super PAC supporting Republican Mitt Romney’s presidential bid four years ago had donated either to Trump’s campaign, to the Republican National Committee via a joint fundraising committee he established with the party or to a pro-Trump super PAC, Great America PAC, according to a USA TODAY analysis of new campaign-finance reports.

That accounts for about 2% of the more than 1,400 people who donated to the pro-Romney Restore Our Future during the 2012 election. Similarly, the analysis found only 23 individuals among the more than 3,400 donors who wrote checks to a super PAC supporting Jeb Bush’s candidacy in this election cycle had given to Trump or aligned groups so far.

Trump largely financed his own primary campaign and his late start in building a donor network is one of the key reasons he delivered such a dismal fundraising performance in May. He ended last month with just $1.3 million in available cash to Democrat Hillary Clinton’s $42 million. Campaign reports showed Clinton with a staff nearly 10 times the size of Trump's, sparking fears among some Republicans about his ability to build a campaign infrastructure to compete with Clinton.

Trump enters general election in weak financial position

Trump and his allies counter that he vanquished 16 other Republicans on a shoestring budget, demonstrating his ability to successfully wage one of the most unorthodox campaigns for the presidency the country has seen.

In all, Trump raised $3.1 million from other donors last month, despite effectively clinching the nomination May 3. By comparison, Romney collected $11.4 million in April 2012, after becoming the GOP’s nominee-in-waiting when Rick Santorum abandoned his bid on April 12.

“It’s fundraising malpractice to have become the nominee on May 3 and not have a low-dollar solicitation go out immediately and do call days and bundling events with high-dollar donors,” said Charles Spies, a veteran Republican lawyer who helped organize Bush’s super PAC, helped found Romney’s super PAC in 2012 and served as CFO of Romney’s 2008 presidential campaign.

“They lost a month that they could not afford to lose,” he said.

Adding to Trump’s woes: Bush, the son and brother of former presidents, quickly locked up the support of many longtime GOP fundraisers, said Barry Wynn, a former chairman of the South Carolina Republican Party and a Bush fundraiser.

He said it’s now hard for Bush loyalists to pivot to Trump, who relentlessly mocked the former Florida governor as “low energy” during the primary. The Bush family has refused to back Trump’s candidacy. (Former first lady Barbara Bush recently called Trump a “comedian” on CBS News, and her son, former President George W. Bush, appears focused on helping retain GOP control of the Senate, raising money for endangered incumbents, such as Arizona Sen. John McCain and New Hampshire’s Kelly Ayotte.)

Wynn said he’ll help Trump, if asked, and predicted that other GOP fundraisers eventually will support their party’s presumptive nominee.

“Even though Trump is not their first choice or even in their top 16, they just don’t want to see the Clintons back in the White House,” Wynn said.

Trump's rhetoric is harsher than previous nominees

Other donors say they have few reservations about Trump.

Restaurant executive Andy Puzder, who donated to Romney’s super PAC during the 2012 campaign and to super PACs backing Bush, Carly Fiorina and Marco Rubio in this election, contributed more than $69,000 on May 25 to the RNC via Trump Victory, Federal Election Commission records show. Trump Victory is a joint fundraising committee Trump established last month with the Republican National Committee and 11 state party committees.

Puzder is the CEO of CKE Restaurants, which owns both the Carl’s Jr. and Hardee’s chains, and he praised Trump’s tax plan as “pro-growth” and called his populist message “refreshing.”

“I think donors are going to come around,” he said. “The threat to our economy from a Hillary Clinton presidency is substantial.”

Some of the Republican Party's most prominent donors, such as Wisconsin billionaire Diane Hendricks and New York Jets owner Woody Johnson, also have signed up to help raise for Trump and the RNC but have not yet appeared among the early donors to Trump's campaign in FEC records.

Trump is moving to correct his fundraising missteps.

He recently sent out what he described as his first fundraising solicitation via email, which his campaign said yielded $2 million in just 12 hours and held two New York fundraisers last week In all, Trump allies said they quickly amassed about $11 million in a few days.

In addition, an array of new super PACs are organizing themselves to either help Trump or to inflict damage on Clinton. New York hedge-funder Robert Mercer, who supported Texas Sen. Ted Cruz’s campaign, has helped establish a new anti-Clinton super PAC, called Make America Number 1.

On Thursday, Trump made his most dramatic financial move, announcing he had converted a nearly $50 million loan to his campaign to a contribution. Spies called that “an important first step” in reassuring skittish donors that he won’t use their contributions to pay himself back rather that win the presidency.

Donald Trump converts $50 million campaign loan into donation

Anthony Scaramucci, a high-profile New York financier and top Romney bundler who now is helping Trump, said the campaign soon will announce a list of dozens "state chairs and co-chairs" who are organizing teams of fundraisers to collect money for Trump.

"There's no shortage of demand for people who want to give Trump money," Scaramucci said. "He going to raise enough money. It may not be the billion and a half dollars that Mrs. Clinton will end up with but it will be enough for him to compete. We've seen what he can do with less money."

"He took out 16 people with $57 million and a staff of 70," Scaramucci said of Trump's success in the GOP primary. "His hit-to-kill ratio is $3.35 million per candidate."

Trump also has indicated that he's likely to contribute more money to his own campaign.

With Election Day looming in five months, veteran GOP strategist Ron Bonjean said Trump should make an even bolder gesture and donate a big sum, in the range of $100 million, to his campaign to “inject some nitrogylcerin into the hearts of the larger GOP donors who are wary that he can pull this off.”