Both those quotes are unclear, but I feel I have parsed them:
He said two main issues are creating that division. First, he said people are more prone to negative party identification; they’re more likely to side with a certain party than with one.
Pretty sure the quote is meant to say:
He said two main issues are creating that division. First, he said people are more prone to negative party identification; they’re more likely to side against a certain party than with one.
That fits in the context of his interview and is what voiceover girl says in the video clip.
The divide may be wide, but Vonnahme said it’s not widespread.
That's just lazy prose. He means that the divide between partisans is wide, but most of the people in the country aren't partisans. Most of the country is apathetic either way.
I also found this gem when listening to the interview:
He has what he calls a "Bug Out Bag" which he'll fill with supplies for himself, his wife, and his cats should they need to leave quickly
Please, Please, Please, Please somebody film One Tubby Tubby bugging out with his wife and cats and his nylon duffle bag of supplies. And the like 5 full bandoleers of shotgun slugs.