The article touches on it - but the answer is the degree to which outward, soundbite “politics” is an expression of that person’s most core beliefs and values.
I have friends from church who vote leftist. I feel they are doing so for emotional or knee-jerk reactions, but it’s hardly the sum of their character. They still believe in Christianity and put their family and local church, work and social connections above political slogans. I can easily connect with these people on the 90% on which we agree vs. the 10% we don’t agree.
I know others for whom “politics” is the sum of their moral system. They don’t seem to have underlying core beliefs, only behavioral habits. For them, the societal fashion and political slogans of the day seem to control their character - and always have them in a state of confusion, anger or depression. It’s very difficult to be friends with them.
How can they believe in Christianity while supporting those whose Prime Directive since 1970 has been "Kill the baby"?