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.

For more than two decades, much of Southern Arizona was represented by Rep. Raúl M. Grijalva, a liberal stalwart who championed environmental causes, supported immigrant rights and advocated on behalf of indigenous communities.