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.

The election to replace the late Rep. Raúl Grijalva is ultimately expected to send a Democrat to Capitol Hill, putting pressure on House GOP leaders.

Republican nominees competed in Arizona's special primary election for the 7th congressional district seat previously held by the late Democrat Rep. Raúl Grijalva.

The next test of who Democratic voters want to see leading the party will take place Tuesday in southwest Arizona, where three leading candidates are offering competing visions in the primary to fill the late Rep.