Harris's campaign raised $190 million in August, according to reports filed with the Federal Election Commission on Friday night, and she spent almost $174 million in August - ending the month with $235 million in cash on hand.

The Trump campaign's report showed that he raised $43 million in August and spent $61 million, with $135 million in cash to spend at the beginning of September.

One of the highest profile groups running ads criticizing Harris is Make America Great Again Inc., which has been funded in large part by Timothy Mellon, a reclusive heir to the Mellon family banking fortune. In mid-July, Mellon gave $50 million to Make America Great Again Inc. - bringing the total that he has donated to the group during the 2023-24 cycle to at least $115 million.

MAGA Inc. raised $25 million in August and spent $90 million. The group's top donors during the period included Wisconsin-based billionaire Diane Hendricks ($10 million), chairman and CEO of Cantor Fitzgerald Howard Lutnick ($5 million), hedge fund executive Paul Singer ($5 million) and Texas philanthropist Annette Caldwell Simmons ($2 million).

Future Forward, the largest Democratic-leaning super PAC, raised nearly $37 million in August. The group received $3 million from Facebook co-founder Dustin Moskovitz and $1 million from Netflix co-founder Reed Hastings. Major environmental groups were also major donors to the group, including the League of Conservation Voters victory fund ($9.2 million), Climate Power Action ($4.5 million) and EDF action votes ($3.9 million).

The Preserve America super PAC bankrolled by billionaire Miriam Adelson, which is also airing ads on Trump's behalf, is expected to raise as much as $100 million for that effort by Election Day, according to a person familiar with the group's plans, but their latest campaign finance reports will not be filed until next month. During the 2020 presidential campaign, Adelson and her late husband Sheldon gave more than $90 million to Preserve America, accounting for the vast majority of the money the group raised.

And Save America, the leadership PAC that has been tasked with paying many of Trump's personal legal bills, reported raising $2,138 but spending $1.9 million to pay lawyers. At the end of August, it owed various legal firms $3.6 million and had $4.8 million in cash on hand.

Despite Harris's cash advantage, her advisers are urging donors and bundlers to push ahead so they can fund what Harris-Walz Campaign Chair Jen O'Malley Dillon has described a "relentless battleground operation" that could determine the outcome in a razor-thin race.