I guess we gotta differ between old and new testament. The old covenant was with the people of Israel. It was between God and a nation. So since God was dealing with humans mostly on the level of nations of course politics mattered because the state of the nation Israel was relevant to whether God would bless or puish them.
But the new covenant is between God and individuals. And sometimes between God and churches. But salvation does no longer depend on being part of Israel. People from any nation can follow Jesus and become friends of God, regardless of how their country is ruled and what policy their government has about gay marriage or abortion or prayers in schools. For those things the people in office who made those decisions will have to answer to God, as individuals. There is no Bible verse thats states new Christians from gentile nations need to change their government into a classical kingdom in order to remain saved, or move to such a place.
Jesus Himself refused to get involved in and used for politics:
in Mark 12:17 (Give to Cesar what is Cesar's and to God what is God's) Jesus states that earthly government and heavenly kingdom are two different realms.
John 18:36-38, likewise.
And when Jesus came to Jerusalem one week before He died there He used the symbolism of a king coming to a city triumphantly to establish that He is king, but He didn't do anything politically. He didn't negotiate the retreat of the romans or start an insurrection against them. He didn't comment on the political situation of Israel at all.