Donald Trump, who rose to political power fuelled by grassroots contributors giving in small increments, is now reliant on wealthy backers, including billionaires Elon Musk and Miriam Adelson, to underwrite his third White House bid.

The former president’s political operation has raised nearly twice as much money — $US514.7 million ($773 million) — from donors giving $US1 million or more to super political action committees, compared to the $US260 million his campaign has raised from small-dollar donors giving $US200 or less, according to the latest Federal Election Commission filings.

The master of small-dollar fundraising, who’s cumulatively raised more money from modest donors than any other politician in history, is losing his touch, the filings show. He brought in only about one-third of the $US321 million Vice President Kamala Harris raised from people giving less than $US200 a pop, third-quarter filings with the FEC show. That enormous sum helped Harris and the Democratic Party raise a record-shattering $US1.1 billion for the quarter, more than double what Trump and the Republicans raised during that period.

Changes to Facebook’s rules for targeting political advertisements have hobbled Trump’s ability to wring cash from its users as effectively as he did during his rise to the White House. Campaigns can no longer directly target followers with fundraising appeals, nor target users by political views, making it harder and more expensive to prospect for contributors.

The switch from grassroots support to billionaire donors also shows how Republican mega-donors have embraced Trump as he has transitioned from party outsider to the GOP standard-bearer. The former president has also brought in new donors, including Musk, who are relative newcomers to political circles.

Loading

The Democrats’ fundraising edge over their Republican rivals means they’ve entered the final — and most expensive stretch — of the campaign with $US63 million more in the bank. Harris is also spending more: $US826 million in the third quarter compared to just $US340 million for Trump.

The massive spending advantage managed to cut Trump’s lead in the RealClearPolitics average of battleground state polls to a fraction of a per cent by October 1, and the two head into the final two weeks of the campaign deadlocked.

Trump has outsourced his ground game, as well as much of his advertising efforts, to super PACs that support him. Fuelled by eight-figure donations from Tesla and SpaceX’s Musk, Las Vegas Sands majority shareholder Adelson, former Marvel Entertainment chairman Isaac Perlmutter and his wife Laura Perlmutter and investor Timothy Mellon, four pro-Trump super PACs combined to rake in $US337 million in the third quarter, more than the $US218 million raised by super PACs whose spending is predominantly aimed at supporting Harris over the same period.