Selection of leadership is, despite the attitudes of many, a Christian issue. Romans 13 gives us insight into the purpose of government and Jesus' admonition to "give Caesar what belonged to Caesar and to God what belongs to God" supports the "two sphere" concept of the separation of church and state. I say "two sphere" because, until Christ returns, we Christians who populate the globe are part of a national state as well as God's Kingdom, the church. It is often difficult to understand the pressure this puts on Christians.
We can take Barton Stone's stance and separate from the state. Stone, if I remember correctly, said Christians should not participate in government--not even vote. Alexander Campbell, on the other hand, was enamored with the nature of the American government. (The difference in attitude was probably due to Campbell's immigrant status.)
Christians must recognize that the nature and form of government has consequences. Reformed thinkers would suggest God absolutely controls all events so the action of individual Christians really doesn't matter. Christians with deistic tendencies would say God set everything in motion and left things to run without his involvement. Neither view, in my estimation, is correct. God interacts with his Creation but a determination to permit truly free choices requires our involvement. He can, and sometimes does, providentially act but sometimes he does not. It is our best interest, and that of our culture, to stand for biblical truth in calling for acts in government which match God's intention for human government.
All too many Christians look merely at the moral qualities of proposed leaders without understanding the cultural milieu in which they operate. Many crude and seemingly immoral leaders understand the purpose of government and the needs of our culture far better than a lot of Christians. Let me remind those reading this that you can't expect non-Christians to act like Christians!!!
I have come to believe Trumps election was a counter-attack to the Progressive Left. Trump's support came from the heartland, the rust belt, and the deep south. These are areas of the country the coastal elites--mostly Progressive urban dwellers--believe are populated by "Wall Mart" shoppers, deplorables, and and those who hold on to their God, guns, and Bibles. He is the result of a battle between those who want an authoritarian nanny state and those of us who believe in individual responsibility and liberty. It is a war between those who are sick of the Left's effort to silence contrary views in the name of political correctness and those who would limit the right to say what you think even if it is crass, biased, or bigoted. It was a reaction against those who think America has to be the world's policeman, pay for the poor judgment of others (in foreign aid and poor market policies). It was a strike against the social justice warriors who fail to understand there is no such thing as SOCIAL justice--there is only justice (getting what you deserve) which requires a blindfold on "lady justice" so the wealthy AND the poor are treated the SAME before the law.
Should Christians care about all this? Yes! Read your Bible. I want you to find SOCIAL and JUSTICE in the same context.
I voted for Donald Trump in 2016, despite his crudeness and his tweets (at least he doesn't sit back and take the crap), and I will do so again in 2020.