Basically, it is with us or against us mentality. Even not having an opinion on some abstract idea, means that you are therefore a perpetrator of this moral wrong.
Not caring about politics is often the worst sin that you can commit to those people, no matter what other actions you have taken in your personal life regarding them or the community.
This is less common in person, and more common with individuals who have arguments with their "friends" on Facebook and the like.
Anyone who makes a post like "If you don't agree with me on X, then unfriend me, as I don't want any people like you in my life!"
