Happy Valley, Ore., population 23,733, played a small but significant role in American politics last week. That’s the hometown of Janelle Bynum, a state legislator who won the Democratic nomination for Congress against Rep. Lori Chavez-DeRemer, one of 17 vulnerable Republicans now representing districts carried by Joe Biden in 2020.
Chavez-DeRemer won two years ago by defeating a far-left Democrat,…