House Democrats are looking to Tuesday's primaries in California as a major test of the anti-incumbency sentiment among their voters. Why it matters: This will be the first time in the 2026 election when multiple House Democrats in their 70s and 80s face off against primary insurgents who have hammered them for their lengthy tenures. California Democratic Reps. Mike Thompson, Doris Matsui and Brad Sherman — all 70 or older — are among those facing tough primary fights with younger Democratic ch