Spite. Yes. Only reason for any sort of protest against the establishment. Obviously.
Interestingly enough that's not what I said.
I would appreciate if someone wants to come along and translate what I've said because that seems to be the only way my points every get across.
Oh, it's not that I doubt that someone would vote for a shitmonger in the other group's primary. I just doubt it would be on a massive enough scale. If given the very real choice to pick John Kasich over Donald Trump and Ted Cruz, how many Democrats would opt for the latter?
1) The democrats could support someone like Chris Christie or the republicans support someone like Lincoln Chaffee. Their ideology isn't scary and they aren't a formidable opponent.
2) It ignores the whole freaking point of primaries which is advocacy for an agenda. The democrats wanted to pick a standard bearer for the agenda of liberalism. They picked a mainstream liberal whom a lot of mainstream liberals admire. The republicans normally would want to pick a standard bearer for the agenda of conservatism but they screwed up.* Other then the current primary they pick a conservative standard bearer that a lot of conservatives admire.
The right to form parties is considered essential to democracy because people need to be allowed to support advocacy for agendas they want. You are suggesting something that makes parties much less about this. It's "advocacy for what you want... sort of... if the other people agree".
*Either they tried to be too cute with their primaries (Trump didn't get a majority after all) or conservativism as we knew it is gone. I think it's probably the former because Trump didn't get a majority of the vote and they seem to be doing fine in downballot races where they have better nominees then Jeb Bush.