In the late 19th century, 65 percent of German Confessional Lutherans voted Democrat. Why is this? Nowadays, most Confessional Lutherans vote Republican because of issues like abortion.
I do not have access to any demographics on voter registration or voting activity of confessional Lutherans, so I cannot address your question specifically.
In general, Christians can face challenges when they vote. There are moral issues on which candidates take a stand in varying degrees. Sometimes Christians might find themselves in a position in which they seem to be voting for the lesser of two evils—looking to vote for the candidate who will have a lesser negative impact on society.
What Christians—and all voters—want to keep in mind is that their votes empower individuals to act in their behalf. With that in mind, Christians want to exercise their civic responsibility of voting and also utilize their divine privilege of praying for those in positions of power and authority (1 Timothy 2:1-2).