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

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.

The comparison illustrates the extraordinary financial stakes of the November midterm elections, when a relatively small number of closely contested races could determine control of Congress.

While every senator holds the same voting power in Washington, the cost of winning that seat varies dramatically depending on the state's population, political competitiveness, and advertising market.

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.

With its relatively small population, Alaska presents an unusual challenge for political advertisers. The enormous volume of campaign spending threatens to consume much of the available television advertising inventory, making it increasingly difficult for campaigns to secure airtime.

The phenomenon is not new. During the 2024 elections, smaller states such as Montana also experienced exceptionally high political advertising expenditures relative to their populations.

Ohio, however, demonstrates that the most expensive race overall is not necessarily the most expensive per voter. The state ranks fifth in advertising spending relative to its voting-age population but is on track to host the nation's costliest Senate contest for the second consecutive election cycle.

Former Democratic Sen. Sherrod Brown is attempting a political comeback after losing his seat to Republican Bernie Moreno in 2024. His latest campaign is attracting even more advertising spending than the previous contest, reflecting the importance both parties place on Ohio's Senate seat.

New Hampshire has also emerged as a major battleground. Democratic Senate nominee Chris Pappas has warned that the contest remains competitive, prompting both parties to invest heavily in advertising aimed at the state's voters.

Texas offers perhaps the most dramatic example of how quickly Senate campaign spending can escalate. Republicans had warned for months that a victory by Texas Attorney General Ken Paxton in the Republican primary would make the state's Senate race significantly more expensive.

Those predictions proved accurate as outside Republican groups spent approximately $131 million over just 17 days in an effort to bolster Paxton's campaign, according to Axios. Additional spending totaling tens of millions of dollars could follow before Election Day.

The Texas spending surge underscores how much national political organizations are willing to invest to defend seats they consider essential to maintaining Senate control.
North Carolina, meanwhile, is moving in the opposite direction.

Sen. Tim Scott of South Carolina, chairman of the National Republican Senatorial Committee, previously suggested that the state's Senate contest could cost as much as $1 billion. Instead, spending now appears likely to remain below $200 million, a substantial figure but far short of that earlier projection.

Republican super PACs have begun withdrawing resources from North Carolina and redirecting money toward states where they see more favorable electoral opportunities.
The shifting financial priorities highlight the difficult calculations facing both parties as Election Day approaches.

Republicans currently enjoy an advertising advantage in several critical contests, particularly Texas and Ohio, where their spending is generating greater audience exposure.