The 2026 US midterm election campaign is expected to be the most expensive ever recorded, with total costs projected to reach nearly $12 billion, according to OpenSecrets, an independent organisation that tracks campaign finance, the BBC reports.
Most of the spending is driven by outside political groups known as Super Political Action Committees, or Super PACs, which are pouring large sums of money into several key races ahead of the election day on 3 November.
The largest individual donor is billionaire businessman Elon Musk, who has spent almost half a billion dollars backing Republican candidates, particularly in Texas, where many of his companies are headquartered.
How much has been spent?
There are rules on how much individuals, parties and political action committees, PACs, can give directly to candidates.
Super PACs, however, can accept unlimited contributions from individuals, corporations, unions and other political committees. They cannot give this money directly to candidates, but they can spend it to support them indirectly.
According to the latest data from the Federal Election Commission, FEC, dating up to mid-October, more than $9.5 billion had been spent in this midterm election cycle.
PACs and Super PACs account for more than half of that amount, at around $5.5 billion, with their spending in the last two months nearly doubled.
Candidates, parties and outside groups must report their spending to the FEC, but the full totals will not be available until after the midterm elections.
However, OpenSecrets has projected that the total will be $11.9 billion, based on trends in past cycles.
This would be around 30% more than was spent during the last midterm elections in 2022.
Which donors have spent the most?
The top 40 donors gave $2.4 billion up to 14 October, according to the liberal-leaning research organisation Brennan Center for Justice, a record figure for that point in a midterm election cycle.
“Spending in the 2026 midterm elections is breaking records, with more money coming from the wealthiest donors and groups in these elections,” says Michael Beckel, an expert on campaign finance in the US.
In addition to individuals, organisations can also donate to PACs. For example, Geosor Corp and the Policy Reform Fund, both founded by billionaire financier George Soros, have given a total of $102 million to liberal groups.
Alongside Soros, former New York City mayor and businessman Michael Bloomberg has been the largest Democratic donor, giving more than $60 million.
Several billionaires, including Jeff Yass, who runs one of the largest trading firms in the world, and Richard and Elizabeth Uihlein, owners of an American business supply company, have given over $100 million to Republican causes this campaign, according to FEC filings.
However, Musk has given more than any other individual, donating almost half a billion dollars since October.
Musk has given most of this sum to a Super PAC he created in 2024 called America PAC, as well as to the Senate Leadership Fund, which is linked to Republicans.
Most of his money has been spent on the Texas Senate race, supporting Republican candidate Ken Paxton, who is running against Democratic candidate James Talarico.
Elon Musk worked for the Trump administration last year and has attended events at the White House since then.
America PAC’s investments in the Texas race total more than $45 million. It has also invested around $10 million in both Senate races in Michigan and Ohio.
What has the money been spent on?
Campaigns and political groups spend money trying to reach voters in a variety of ways, including hiring staff to make contact with voters on the ground and organising campaign events such as rallies. They also spend money on internal polling.
However, most of the funds are spent on advertising, especially on television.
In this cycle, $11.15 billion has been spent on advertising by the end of October, according to advertising tracking firm AdImpact.
“Traditional television remains the main beneficiary of advertising spending, although spending on digital ads continues to grow,” says Beckel.
Similar to Musk’s spending, AdImpact found that most of the money has been spent on advertising in the Senate races in Michigan, Texas and Ohio, followed by Iowa and Maine.