These tests are literally Puritan. It is so ingrained in the American fabric that I am not sure either side sees how it short-circuits thought and the careful consideration of issues necessary to make sane decisions.
For example, I told a former friend that Mark Warner of Virginia or Phil Bredesen would have gotten a nomination at some point if the left really wanted to win big. Seemed a pretty innocuous a comment to me since both guys won red counties by huge margins in state wide elections. Within 5 minutes he was telling me that I was like the Germans who stood by as Hitler took power for supporting GOP-lite candidates.
After that, I thought my conservative uncle would get a chuckle out of this story, so I relayed it to him over some whisky. Instead of seeing the absurdity in it, he agreed with my liberal friend about the severity of my mistake. His reason, though, was because far-left liberals like Bredesen and Warner would allow so many babies to be murdered. Then he re-thought, and said that it would actually be worse than the Holocaust to elect people like that to national office.
Welcome to America, I guess. Lesson one, avoid politics at work, church, and family or public gatherings.