A very real example of where Christian Nationalism would take us can be found in Uganda
https://signalpress.blogspot.com/2023/06/a-glimpse-at-where-christian.html
The African nation of Uganda, a political disaster that once "elected" a President who admired Adolf Hitler, has been heavily influenced by American Evangelicalism, largely because of intense missionary efforts and large amounts of financial support. The result of that influence was its national government, under President Yoweri Museveni, passed a law that makes being homosexual a criminal offense with the penalty of life in prison, and "aggravated homosexuality" being a death-penalty offense. Republican Senator Ted Cruz, who is not politically liberal by any stretch of the imagination, publicly criticized the law, using terms like "horrific, wrong, a grotesque abomination."
With Cruz, it's hard to tell whether his words are political rhetoric spoken to gain favor with a more moderate constituency he knows he and his party must have to win elections, or whether it comes from genuine conviction. I lean much more toward the former explanation, since I don't think Cruz has any genuine conviction that is a matter of real conscience and not something aimed at getting votes somewhere down the line. But he made his feelings known publicly, and apparently spontaneously, and drew the ire of one Tom Ascol, a caustic, hard-line Calvinist Southern Baptist from Florida, who pounced on Cruz's comment and threw Leviticus 20:13 back in his face.
If Ted Cruz is a liberal, then that is quite a definitive statement about what hard right Christian nationalism looks like, and what government would look like under its influence. It would bear absolutely no resemblance to the Christian gospel preached by Jesus. It would be a cruel, judgmental, evil system of government, to put it mildly. It would be worse than German National Socialism or Soviet Marxism.