In 2012 — the first presidential election after the decision — outside groups reported $1.25 billion in independent expenditures to the FEC. By 2024 that figure had reached $4.4 billion, more than triple the 2012 total and a record for any cycle. Even the midterms tell the story: $788 million in 2014 grew to $2.3 billion in 2022.
Independent expenditures are the most direct measure of outside money: they are the ads and mailers that expressly support or oppose a candidate, paid for by groups acting independently of the campaigns. The FEC totals below are reported figures, not estimates.