That's an absolute hard no from anyone who supports Israel's right to exist as the (sole) homeland for Jews.

The US Civil War is not at all a relevant parallel. There, it was a war between brothers who shared the same religious and ethnic background but had a profound disagreement over slavery.

Here, it's a struggle between two very different groups, with different religious, ethnic, historic, cultural, and language backgrounds. Trying for a one-state solution would work even less well than Lebanon's unhappy example.