Clinton's campaign had $42 million in the bank as of May 31, according to its report filed with the Federal Election Commission Monday. Her super PAC Priorities USA has $52 million.
Trump's campaign has $1.3 million.
The gulf emerges as Democrats lay out plans to spend that cash on an onslaught of television advertising that Trump has shown no urgency in matching. Clinton and her allied groups are planning to spend $117 million between Tuesday and Election Day on television -- much of it anti-Trump television -- while Trump and his groups have $700,000 in time awaiting him thus far.
Trump, who just began actively fundraising last month with a $3.1 million haul, also has a super PAC benefiting him -- but it has only $500,000 in the bank. Two other big-money groups will not be required to disclose their fundraising position until next month.
The New York billionaire can presumably close the money gap with one check, but hasn't indicated he will do so. The candidate and his allies have consistently emphasized the ability to run a leaner campaign than Clinton's.
On Tuesday, Trump appeared to dismiss the fundraising issue, telling NBC's "Today," he's willing to "do what I did in the primaries."
"I spent $55 million of my own money to win the primaries. 55, that's a lot of money by even any standard," Trump said. "I may do that again in the general election."
Trump added that he had "a lot of cash" but added that "it would be nice to have some help from the party."
There is good reason to think the May gap will close substantially: The two remaining pro-Trump groups are expected to announce big hauls next month, and Trump in June launched an aggressive fundraising swing with 10 events in nine days that raised more than $8 million
, according to one source. And his joint fundraising agreement with the RNC -- which allows for checks at $450,000 at a time -- was only born in the final days of May.
Yet Trump is attempting to raise $500 million even as he essentially builds a money network from scratch. And questions persist about whether he will even hit that low target.
That has spawned a new round of frustration from Republican elites and donors, which spilled out Monday with the firing of Trump's campaign manager, Corey Lewandowski
. Some Republicans have begun to wonder whether they can depose Trump at the convention, with anti-Trump delegates and supporters beginning to publicly organize their efforts.
RNC suffering as well
Yet even more dire is the position of the party: Trump last month began raising money for the Republican National Committee through a joint fundraising agreement.
But despite Trump's promises that money is pouring into the GOP central office, the RNC had only about $20 million cash-on-hand at the end of the month -- $40 million less than the RNC did as of May 2012, when Mitt Romney, a prolific fundraiser, was topping the ticket. And it raised about $20 million less in May 2016 as it did in May 2012.
The RNC got about $3 million in the first days from the joint Trump Victory account, but much of that cash is earmarked for things like building funds and convention services and cannot be used on Trump's general election campaign. Several prominent Trump allies, including Los Angeles investor Tom Barrack and casino magnate Phil Ruffin, cut six-figure checks to the RNC.
The RNC explained its cash position by pointing to their plans to invest cash early into their ground game, rather than hoarding it for television ads late in the campaign. And the RNC was still in better fundraising shape than the Democratic National Committee, which raised about $12 million last month and had about $9 million on hand.
Several other conservative groups that historically have spent on behalf of the Republican presidential nominee appeared well-funded in Monday's reports, but have said they are not yet comfortable spending their war chest on Trump's campaign and will instead spend down-ballot.
Trump's main group so far, Great America PAC, raised $1.4 million in May, records show. By comparison, Clinton's super PAC, Priorities USA, raised about $12 million, more than it has in any other month. One pro-Trump group that is expected to be the main big-money vehicle though, Rebuilding America Now, has said that it has amassed $32 million in pledges, a sum that would begin to shrink the gap between the two camps.