The republican / democrat, two-sided coin system that has possessed our US government is not in scripture and it’s not in the constitution.
It is slowly lulling us into a religious-king centered government. I believe If we continue to let it evolve, it will take over and eliminate the constitution.
It’s not part of the kingdom of Jesus Christ, so no we (Christians) are not obligated to get sucked into it by duty or by guilt or to even participate in it, if we do not want to.