I think this is much ado about nothing. It's a harmless comment in an email where Jerry Duncan is just being Jerry Duncan.
If there are any Republicans that really object to this behavior and want to run against Duncan next time, so be it. If the voters don't like it they can vote for someone else.
Unlike the other case, which involves actual wrongdoing by the politician and where his supporters are inciting "war" to defend him at all costs.