It would be great if the country could be split up between the conservatives and liberals.
Only if they could each bar entry to the other. Otherwise, the split would be meaningless.
God understood this principle with his nation Israel. It seems to some extreme that he would be so severe with the people which occupied the land God gave to Abraham's decedents, but a pure, undefiled standard was necessary for any national identity. Even with this, they rebelled and fell from his favor. How much more if they were allowed to intermarry and adopt the customs of the surrounding nations.