Becoming president of the US takes a great deal of money. To get that money, candidates have a number of options.

Candidates can finance their campaigns with their own money. Alternatively, they can raise money from private donors.

Another source of funding comes from political action committee groups, better known as PACs or super PACs.

The final option is to get government funding. But this comes with strict limitations on spending, so mainstream candidates have avoided it in the last few elections.

How much has Kamala Harris raised?

Democratic candidate Kamala Harris has brought in over $906 million (€838.8 million) up to September 30, according to numbers put together by OpenSecrets, a Washington-based nonprofit that tracks money in US elections. This includes contributions to the Joe Biden campaign, though fundraising really took off after he stepped aside in July. 

Added to this is more than $359 million that outside groups have raised up to September 22 to support Harris, which means over $1.27 billion has gone toward Harris' campaign war chest.

Nearly 56% of this has come from large contributions. Individuals have stumped up around 44% of the total through smaller contributions of under $200.

How much has Donald Trump raised?

Republican candidate Donald Trump hasn't raised nearly as much. His official campaign has brought in $367.1 million, roughly 60% less than Harris.

Outside groups have added another $572.8 million to that, bringing his total funding to just under $940 million, according to OpenSecrets.

Trump is very dependent on the support of the ultrarich, with larger contributions making up more than 68% of his available funds.

What about spending on Congress?

In the past two presidential elections, Trump was outspent by his rivals. He nonetheless won against Hillary Clinton in 2016 before losing to Biden in 2020.

That discrepancy shows how cash matters but cannot seal the deal alone, said Dan Mallinson, an associate professor of public policy and administration at Penn State Harrisburg in Pennsylvania. 

Still, donations are incredibly important as presidential campaigns "have become billion-dollar affairs," Mallinson told DW. "Candidates, parties, political action committees and other organizations all need to raise significant amounts of money to run national campaigns."

But it's not just the former president and vice president who are raising money during this election cycle. Of the 100 US Senate seats, 34 are up for election this year. In the House of Representatives, all 435 seats are up for grabs.

For their own election campaigns, all Senate candidates together have raised $1.38 billion, calculated OpenSecrets. Collectively, the House of Representative candidates have raised $1.78 billion.

Who can donate to presidential campaigns?

The Federal Election Commission has strict rules about who can and cannot contribute to the candidates.

Only US citizens or green card holders can contribute to a party or presidential candidate. That means all foreign nationals are barred from donating in any way.

For those individuals who can donate, there are limits on the amount they can give. 

Federal government contractors, corporations, national banks, labor unions and nonprofit organizations are likewise barred from contributing directly to candidates or parties in federal elections. 

What are PACs and super PACs?

Political action committees (or PACs) have long been a part of the American election system. These pressure groups pool contributions to work on behalf of candidates or ballot initiatives. Donations are limited, and donor lists must be disclosed.

But campaign finance regulations changed drastically in 2010. That year, the US Supreme Court threw out restrictions on corporations and unions to fund campaigns, because of their right to free speech.

After that decision, corporations and unions were free to donate whatever they want, giving rise to the super PAC. These groups can raise unlimited amounts from individuals, unions or corporations, and these donations are anonymous.

Importantly, PACs and super PACs cannot donate directly to a candidate and must act independently, though some of the rules on coordinated get-out-the-vote canvassing have been relaxed.

Problems with big campaign contributions

For many voters, the campaign donation system gives the impression that cash equals easy access to politicians. This could result in corruption, or erode trust in democracy.

Rich Americans like Melinda French Gates and George Soros have donated millions to groups supporting Harris, or founded super PACs of their own.

The Financial Times calculated that another group of billionaires — Elon Musk, Timothy Mellon, Miriam Adelson and Richard Uihlein — have given a combined $395 million to pro-Trump super PACS.

Whether these mega-donations equal power is a complicated question. 

"It's not straightforward that money buys votes and policy," said Mallinson, adding that this money likely means donors get political access when issues they care about are being debated. "But that still does not mean that the donors will get everything that they want." 

What do campaigns spend money on?

With hundreds of millions to spend, campaigns and pressure groups have a lot of decisions to make. Since the election is so close and likely dependent on a handful of votes in swing states, campaigns are spending most of their money there. 

These states are being inundated by political ads. Residents are likely to get calls from campaigners or a knock on the door from someone trying to convince them to vote one way or the other.

Looking back at the 2020 election gives a good idea of how campaigns are spending their mountains of cash, with the bulk going toward advertising.

Four years ago, around 56% of spending was on media, 10% on fundraising and nearly 17% on campaign expenses and salaries, according to figures tallied by OpenSecrets. Another 6% was for administration, while 4% went to strategy and research. The remainder was listed as "unclassifiable."

Campaign spending in 2024 will likely follow a similar pattern.

Edited by: Martin Kuebler