It’s useful to understand why the Kavanaugh vote mattered so much to these Republican voters. First, Democrats and Republicans seemed to view the values at stake differently. Many Democratic voters viewed Democratic senators as protecting a victim and standing up to a sexual predator.
However, many Republican voters viewed Democratic handling of the Kavanaugh confirmation as a violation of basic fairness. They were horrified by the cultural precedent that Democrats appeared to endorse: that an allegation without evidence beyond the memory of one individual person could be enough to destroy a person’s reputation forever.
Many Democrats did not believe these accusations would destroy Kavanaugh’s reputation or life, and some didn’t care if it did, but many who voted Republican thought differently. They did not believe that Kavanaugh was getting his just deserts, but was being punished regardless of the facts. This violated their deeply felt ideas about basic fairness and they reacted by heading to the polls.