Yes, follow the line from Lincoln to the present Republican party. But so what? Except for rhetorical purposes, which I don't disdain.

There's no reason decent people who disagree politically should detest each other, just because they adhere to different parties which represent different views as to how society shoudl be organised.

There is every reason they should encourage each other in getting rid of the malevolent parasites who tend to crawl into positions of power and influence in all organisations. (Including non-party organisations.)

I've just been reading some Don Camillo stories. Don Camillo, the Parish Priest, and Peppone, the Communist mayor - that's the model for how political enemies should deal with each other.