'Worry about that': Insider exposes dark fear behind Trump's troubling hoarding habit

President Trump's reluctance to unleash the hundreds of millions of dollars sitting in his political accounts may boil down to a simple calculation: he's worried his leverage is about to fade — and his ability to rake in more money, according to a new report.

Republican candidates counting on a cash infusion from Trump's super PAC, MAGA Inc., have been left waiting with empty hands, the Washington Post reported Thursday.

Advisers have told nervous allies the PAC — holding more than $400 million as of late July — would open its wallet once the campaign hit full swing after Labor Day. That hasn't happened, and Republicans increasingly suspect Trump, who must sign off on every dollar spent, has different priorities.

"Theories about what Trump wants to do with the money cover a broad range of possibilities, including protecting his political influence in the next presidential race by passing on the money to his chosen successor and saving up for legal fees, post-presidential travel, events and pet projects, such as his library," the report notes. "Trump’s Miami library is projected to cost at least $1 billion, the most expensive presidential library construction to date."

According to a White House insider, the president is worried his ability to obtain more donor cash will dry up as he enters last term "lame duck" territory.

"Donors have started holding back on giving more money to the super PAC while it sits on earlier contributions, according to people familiar with the matter," the Post reported. "Fundraising accounts associated with the president — such as his super PAC, and funds for his inauguration, White House ballroom and Freedom 250 events — have been inundated with donations from companies looking to get in Trump’s good graces, a dynamic that is likely to change."

Many of the swing constituencies that helped Trump win back the White House are now struggling with disappointment, spurring concerns that MAGA Inc.’s massive amount of cash won't be able to protect GOP majorities in November, according to the Post.

“I worry about that, for sure,” Senate Majority Leader John Thune (R-SD) told a CBS affiliate in South Dakota. “I’m a realist, and I just think you — I don’t ever try and sugarcoat things. I think it’s a competitive environment right now.”