Las Vegas Sands Corp. Chairman and CEO Sheldon Adelson has been a vocal supporter of presumptive GOP presidential nominee Donald Trump. (Jeff Scheid/AP)

Leading Republicans are increasingly anxious that presumptive GOP presidential nominee Donald Trump is lagging far behind Democratic front-runner Hillary Clinton when it comes to having an organized network of big-money allies, triggering a chaotic scramble to set up a clear super PAC structure.

Because Trump condemned such entities throughout the primary contest, there is no dominant group ready to channel the resources of the billionaires lining up to back him, including casino magnate Sheldon Adelson, who has signaled plans to inject tens of millions into the race.

That leaves Trump advisers, GOP strategists and major donors puzzling over a key strategic question: Where should the six- and seven-figure contributions go?

Clinton’s allies have built a deeply funded constellation of independent groups, and her main super PAC is readying a $136 million ad blitz that will kick off Wednesday. The fundraising imbalance is acute: The top three super PACs supporting Clinton had collected about $80 million through the end of March, compared with just $8 million by several potential Republican presidential players including American Crossroads, according to Federal Election Commission filings.

Republican presidential candidate Donald Trump has sent mixed signals about super PACs that have formed to support his candidacy. (Ricky Carioti/The Washington Post)

The dynamic has triggered a rush to identify the right organization to harness Trump’s rich allies and run a sophisticated independent campaign. Two rival super PACs are in the mix, but both are newly formed and are viewed with skepticism by major donors and their advisers.

The free-for-all environment alarms veteran party strategists who have recently signed on to try to help Trump win the White House.

“If you have many elements trying to do their own thing, it can confuse the message of the campaign,” said Ed Rollins, who was Ronald Reagan’s campaign director in 1984 and is advising Great America PAC, one of the pro-Trump groups. “We’re all marching forward without clear direction at this point.”

Amid the jockeying, big donors who have expressed public support for the real estate developer have yet to be contacted.

“I haven’t heard from anybody,” said Dallas investor Doug Deason, whose father, billionaire technology entrepreneur Darwin Deason, gave large sums to super PACs allied with former Texas governor Rick Perry and Sen. Ted Cruz (Tex.). “I think they’re just really unorganized. They need to get on it.”

The lack of a major super PAC vehicle is a source of concern among top Trump advisers, some of whom have contacted experienced strategists in recent weeks to gauge their interest in launching a new entity, according to multiple people familiar with the conversations. Such outreach is potentially risky, since federal law prohibits a candidate’s agent from establishing a super PAC.

As of Feb. 29, super PACs have spent more than $226 million on the 2016 races. Here's what a super PAC can (and can't) legally do. (Sarah Parnass/The Washington Post)

When asked if he was aware of such talks, Trump campaign manager Corey Lewandowski did not respond directly, writing in an email, “Mr. Trump continues to disavow all Super PAC’s.”

That unequivocal statement probably will further confuse major donors, who interpreted Trump’s softening rhetoric on super PACs in recent media interviews as a sign that he was open to their support. (“I know that people maybe like me and they form a super PAC, but I have nothing to do with it,” Trump told NBC last week.) On Saturday night, Trump retweeted a link to a New York Times report that Adelson is willing to spend as much as $100 million to boost his bid.

Senior Republican strategists think that it would be extremely difficult for Trump to be competitive in the general election without the help of a well-financed outside operation. Trump is just now assembling a fundraising team to try to raise $1 billion in five months for his campaign and for the Republican Party, a steep goal.

Outside operatives said they plan to push forward with their efforts to try to match the pro-Clinton operation.

“From our perspective, we see it as necessary,” said Doug Watts, national executive director of the Committee for American Sovereignty, a new pro-Trump super PAC that launched last week.

Democrats have a significant head start. During the past year, a network of super PACs and advocacy groups allied with Clinton has been aggressively raising money and plotting a strategy to provide her with air cover and ground support in the general election. The biggest super PAC, Priorities USA Action, has reserved $136 million worth of television, radio and digital advertising that will begin Wednesday, as CNN first reported, and extend almost continuously until Election Day in seven battleground states.

“We want to do even more, and we will need to do more because we’re running against a billionaire who will surely have help from Republican super PACs and special interests,” said Priorities spokesman Justin Barasky.

The group is working closely with major national advocacy groups such as Planned Parenthood, Emily’s List and the League of Conservation Voters, which are running their own well-funded campaigns to promote Clinton. Labor unions are also readying massive voter mobilization programs.

Meanwhile, the most influential outside groups on the right are on the sidelines of the presidential race. That includes the Koch political network, which aims to spend $900 million in the run-up to the 2016 elections. Billionaire industrialist Charles Koch has been critical of Trump, and the network’s resources are expected to boost conservative congressional candidates rather than the Republican presidential nominee.

That dynamic reflects a widespread lack of consensus in the donor community about how to engage: Some are appalled by Trump and have decided to focus only on Senate and House races, while others find him distasteful but do not want to see Clinton elected.

Standby mode

The suite of Crossroads organizations, which together raised $300 million in the 2012 elections, has yet to determine what role it will play in this year’s White House contest. President Steven Law did not rule out getting involved in the race, but he said that the group is still assessing donor interest and conducting research about how it can be most effective. One possibility could be tying an anti-Clinton message to its campaigns supporting Republican senators.

“Holding the Senate majority is going to be our North Star, so everything we’re currently planning to do relates to that fixed point on the compass,” Law said.

Similarly, a new organization called Future45 that was formed last year to produce quick-strike ads against Clinton is in standby mode. Some of the group’s biggest backers, including the Ricketts family and hedge fund billionaire Paul Singer, were major donors to an anti-Trump super PAC this year.

Adelson has been one of the most vocal Trump supporters within the billionaire class, writing in a Washington Post op-ed last week that “it’s time for all Republicans to mount up and back our nominee.” Other Trump backers who have the capacity to give enormous sums include Oklahoma oil baron Harold Hamm, Texas financier T. Boone Pickens, Home Depot co-founder Ken Langone and casino executive Phil Ruffin.

But donors are trying to assess whether there is a political operation that they trust to use their funds effectively. Some of the biggest givers may set up their own operations, according to strategists familiar with the discussions.

Great America PAC, launched this year by jewelry company chief executive William Doddridge, has had the largest presence among pro-Trump groups. But the organization has seen upheaval in its ranks, including the departure of tea party leader Amy Kremer and strategist Jesse Benton, who was convicted of conspiracy and campaign finance violations in a case stemming from the 2012 presidential campaign.

PAC officials said the group’s leadership has stabilized with the arrival of Rollins and other veteran political strategists, including Brent Lowder, a former executive director of the California Republican Party.

Pickens is set to host a briefing at his Texas ranch next month for prospective donors to the group, and some longtime GOP backers, such as Minnesota broadcasting executive Stanley Hubbard, have pledged to give money.

Great America says that it has amassed a database of 2 million Trump supporters and promises to invest heavily in TV ads and grass-roots activities.

“The operation that people should be looking at is the one that has the infrastructure to ramp up in the swing states, and that’s us,” said co-chairman Eric Beach, who said he does not think that there is a need for two super PACs.

Last week, the Committee for American Sovereignty launched with the aim of raising $20 million by the July convention.

“There might be some confusion and some donors may get multiple solicitations, but this is standard operating procedure,” said Watts, the group’s national executive director. “I expect two or three or maybe even four very legitimate super PACs that are in support of Trump.”

The organization has its own issues: Its chairman, former California state senator Tony Strickland, is facing a proposed $80,000 fine by the state Fair Political Practices Commission for circumventing contribution limits in a 2010 campaign. In an interview, Strickland said that he is in negotiations with the agency and that the matter will be resolved this week.

Among those backing the new super PAC is Nicholas Ribis Sr., a former chairman of Trump Hotels and Casino Resorts, along with investor Nick Loeb and California businessman Tim Yale. Watts said he has fielded a surge of interest from potential contributors in recent days.

“There are plenty of donors out there who have been sitting on the sidelines for months and months and months, wanting to get involved,” he said.

Tom Hamburger and Philip Rucker contributed to this report.