embitter

People on the right get embittered by people on the left.

Vance cast his fellow Appalachians as stuck and embittered with a country that moved on without them.

He has served as a historical and cultural consultant since “The Last Samurai,” in which Tom Cruise plays an embittered U.S.

Here's the breakdown of the embittered relations between the frenemies turned outright adversaries:

Germans were embittered by the way so many German speakers were placed under the rule of other countries.