The Democratic primary to fill the seat vacated by the death of Representative Raúl M. Grijalva in Arizona’s deep blue Seventh Congressional District in Tucson will be a contest between legacy and change.

A special election primary in Arizona’s 7th District on Tuesday was the latest flare-up of the Democratic Party’s clashes over age and experience as candidates vie to replace the late Rep. Raúl Grijalva.

Tensions within the Democratic Party over age, representation and experience have roiled a special election primary in southwest Arizona, where a young, social media-savvy activist is taking on the daughter of Rep.