Over the past month, several progressive Senate candidates have won their primaries despite being significantly outspent. In Massachusetts, Senator Ed Markey, 80, defeated Representative Seth Moulton, 47, overcoming concerns about his age by emphasizing his support for policies such as the Green New Deal and Medicare for All. Markey faced a nearly 2-1 ad spending disadvantage, with Moulton and supporting groups spending $7 million compared to $3.9 million for Markey's campaign, according to AdImpact.
This trend was also evident in other Democratic primaries. In Michigan, Representative Haley Stevens and outside groups spent $31.3 million on ads but lost to former public health official Abdul El-Sayed, who had $6.6 million in ad spending. In Minnesota, Representative Angie Craig had an ad spending advantage of $19.7 million over Lt. Governor Peggy Flanagan, who won with $4.7 million spent on her behalf. In Florida, state Representative Angie Nixon, a democratic socialist, defeated former National Security Council aide Alex Vindman, despite spending only $66,000 on ads compared to Vindman's nearly $2.2 million.
These results indicate a shift in Democratic voter preferences following the party's defeat in the 2024 election. In Massachusetts, besides Markey, Representatives Stephen Lynch and Richard Neal also defeated younger challengers in their primaries, although both received less than 60% of the vote. An NBC News analysis found that from 2000 to 2024, about 8.7% of House members who ran for re-election received less than two-thirds support in party primaries, with a slightly higher percentage among Republicans. In 2026, nearly 20% of House Democratic incumbents fell below this threshold, with 11 House incumbents, including seven Democrats, losing their primaries this year. Additionally, two Republican senators, Bill Cassidy of Louisiana and John Cornyn of Texas, were denied renomination.