Older Democrats walloped by midterms anti-establishment revolt

House Democrats who have comfortably held their seats for decades are suddenly finding the ground shifting beneath their feet as primary voters revolt against the party's old guard. Why it matters: The anti-establishment revolution that has swept Democratic primaries this year is poised to drastically alter the makeup of the party caucus and Congress as a whole. Rep. John Larson (D-Conn.) became the latest victim of this trend: The 78-year-old lost his primary by more than 20 percentage points…