Usually the right winger types are pretty heavily into prosperity gospel and feel that their faith entitles them to whatever they are into. Many of the loudest folks are associated with unaffiliated parishes, where there is no higher earthly authority to reign in the pastor.

You also see a lot of extreme behavior tied to single issues like abortion or birth control. In short, people very passionate about an issue will often veer (or be steered) into an ends justify the means type philosophy.