An Arizona special election primary Tuesday to replace the late Rep. Raúl Grijalva is the latest flare-up of the Democratic Party’s clashes over age and experience.

Arizona Democrats on Tuesday will choose their nominee to run for a vacant U.S. House seat in September, as the party grapples with demands for generational change and divisions over just how progressive it can be in the era of President Donald Trump.

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.