Rep. Chris Pappas won the Democratic Senate nomination in New Hampshire on Tuesday, defeating first-time candidate and self-described socialist Karishma Manzur. The result matters because Democrats must hold this open seat to protect their chances of retaking the Senate majority, and the contest was one of the final flashpoints in a bruising primary season that has repeatedly pitted the party's progressive and establishment wings against each other.

Pappas is seeking to succeed retiring Senator Jeanne Shaheen and enters the general election as the clear frontrunner, backed by the party establishment and unions; Republicans have not won a Senate race in New Hampshire in 16 years but see the vacancy as a prime pickup opportunity. Manzur, a biochemist and Democratic Socialists of America member, campaigned on universal healthcare, a $20 minimum wage, abolishing ICE and ending military aid to Israel, accusing Pappas of being too close to AIPAC; Pappas defended his record and cast himself as a pragmatic candidate for centrist voters. He will face either former senator John E. Sununu or former senator Scott Brown in the general election.