It is absurd that anyone can be so internally compromised that they can claim to be a Christian and a Democrat. The two positions are polar opposites.
Consider:
Hitler and his Nazis were responsible for the deaths of 11 million people. Democrats are responsible for the deaths of 55 million babies. Who is more evil?
The Democratic party supports abortion. Terminating the life of the most vulnerable member of the human race! It is part of their party platform. Christians DO NOT support the killing of innocents. How can someone resolve this conflict internally without destroying some part of their soul?
The Republican party does not support abortion. Just as the Democrat party was/is the pro-slavery party, the Republican party has always been the anti-slavery party.
A person may try to rationalize their support for the Democratic party by saying they never killed anyone, but the Nazis who supported Hitler, even though they may have never killed anyone, are just as responsible for the 11 million deaths. They supported the system that allowed it to happen.
For many years after the fall of Hitler’s Nazis, all Germans, not just the Nazis, were treated as pariahs around the world. While the German people claimed ignorance and therefore innocence, the rest of the world did not agree.
You may try to claim that “I just do not understand” and you are correct but history will judge the Democrats accordingly.