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.

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.

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.