Several people I know have been told they cannot be a Christian and a Democrat. I am both.
I was raised in a Republican family but a few years ago, I realized that party no longer represents my own Christian values. Jesus' parable of the sheep and goats in Matthew 25 makes it clear His followers must seek to help and protect society's most vulnerable, including children, the elderly, the poor, and minorities. The Democratic party, with its support for food stamps, reasonably available health care for all, protection of Social Security and so many other social and economic justice issues, is the political party that best fulfills that calling for me.
Some will say I am supporting "baby killers." I am far from a fan of abortion, but history makes it clear abortions will continue even if illegal; they will simply be more dangerous. I believe giving women adequate means to support their children is far more likely to help desperate women choose life.
We Christians who are Democrats do not condemn Christians who vote Republican; we ask the same courtesy of you who are Republicans.