These Are America's Most Expensive Senate Races: Where Republicans and Democrats Are Spending the Most

Maine leads the country in Senate advertising spending per voting-age resident, followed by Alaska, where approximately $76 million in political advertisements are scheduled to run during the election cycle. (Credit: Jeff Kowalsk/AFP via Getty Images)

Winning a seat in the U.S. Senate has become extraordinarily expensive in 2026, with political parties and outside groups pouring hundreds of millions of dollars into a handful of competitive races.

In Maine, for example, Democrats and Republicans are spending on Senate campaign ads enough to give every voting-age resident $167, according to an Axios analysis of advertising data from AdImpact.