Your comment that "[t]he GOP is currently the only viable party that stands for biblical principles, such as life, justice and nationalism" seems to affirm my concern. What worldly politics stands for is worldly politics. Can Christians support these parties where they affirm godly values? Sure they can (and should). But not under the misconception that what those parties are standing for are "biblical principles".
Your argument is with Paul, not me. Paul said governing authorities were from God and he laid out the principles that guide them. They are indeed biblical principles. We can apply them to governments and judge which ones are following and which ones aren't.
I do not support the GOP. I support the agendas of the GOP insofar as the expression of my faith materializes in such support. That is the difference between standing for Christ and standing for a political party as an extension of one's faith.
This is all semantics. If you support the GOP's policies of nationalism, life, etc., you support the GOP. You're no better than any other GOP supporter.