Mike Gravel won his first U.S. Senate term by defeating incumbent Sen. Ernest Gruening, a former Alaska territorial governor, in the 1968 Democratic primary.
Notes on verification
Confirmed by multiple independent, reliable sources including CBS News, NPR, and Wikipedia, with consistent details on the primary upset and Gruening's background. [cascade flags: wikipedia_dropped_other_sources_exist | tier=silver indep_score=0.7 clusters=2 claim_tier=notable]
Sources
- Mike Gravel, former US senator for Alaska, dies at 91 (seed:politics_and_current_events)
- https://www.npr.org/2021/06/27/1010702706/mike-gravel-former-alaska-senator-and-anti-war-advocate-dies-at-age-91 (corroboration)
- https://www.cbsnews.com/news/mike-gravel-dies-former-senator-alaska-presidential-candidate/ (corroboration)