Unless you've been very careful to only surround yourself with people who share your exact views, you probably do know some. They just don't speak up, because: what's the point debating it with you?
For example, community supported agriculture programs cross traditional political boundaries.
35% of Democrats are pro-Flock.
54% of Republicans.
If someone doesn't know a pro-Flock person, he/she is living in a bubble. Agreed with the first responder: You likely know multiple people, but they're scared to reveal themselves.
No matter what it is, if the other party holds the strict belief that they can't be wrong, I avoid to debate them privately.
And this attitude is exactly why they get away with it.