I had to google this Gothard movement. Never heard of it before. Sounds like a cult.
it's extremely subtle, though. they hold these conferences, of which i attended part of one, mostly out of curiosity.
the deceptive thing is (at the time) i couldn't find a single flaw in the logic of their biblical handouts. they are conservatively written, lots of scripture and from what i can recall, thought there was decent stuff offered. unfortunately, they have a gift for pushing legalism to a whole new level.
one example i can think of is that my mom and sister refused to ride in my truck while i was listening to some secular music i had playing. i quickly attempted to appeal to them, offering to change the music to a christian station. unfortunately, there was percussion in the music, and therefore, of the devil, so i turned off my stereo (considering i was fresh out of classical at the moment). i asked if everyone in the family believed in this, and i was told "well, not everyone is that spiritually mature yet" or some kind of similar statement.
also, because my sister decided to get married to someone (another christian) and didn't follow the "courtship rules" the scars from that whole debacle are still healing. i had no idea whether the rest of the family would be showing up, or what. she was practically cut off from the majority of the church because of her "defiance".
also, a number of them are hardcore into "God planning your family" to the extent that many (if not all) feel birth control is sinful. as a result, many have rather large families.
i can speak of these things now only because they're all out of the gothard-ites--thankfully everyone's been sprung free.