Republican candidates have raised less than their Democratic opponents in 12 of the 13 Senate contests considered most competitive, but conservative outside groups have more than offset that gap with a surge of spending before the Nov. 3 election.
From Sept. 28 through Oct. 11, advertising benefiting Republican Senate candidates totaled $267 million, compared with $196 million for Democrats. The $70 million difference was narrower than the $113 million gap recorded in the previous two-week period, while broadcast advertising favored Republicans by about 146,000 spots to 122,000.
The spending advantage has been especially pronounced in Texas and Ohio.
Democratic candidates have posted large fundraising totals in several major contests.
The advertising contest is also changing in form. Across the Senate, broadcast advertising in 2026 had reached nearly 1. 5 million spots by Oct. 11, the second-highest total recorded for a comparable cycle.
Artificial intelligence has become part of the campaign advertising mix. At least 220 AI-generated or AI-enhanced ads had been identified across 34 states, backed by more than $137 million in spending; 81 percent of those ads were sponsored by Republican candidates or groups, and 27 percent carried an AI disclaimer. The tracking is considered an underestimate because some uses of AI cannot be identified reliably.