Too many ministers are motivated by politics, rather than Christianity.
The point would be that their politics COULD NOT be separated from their belief system. You either believe, or you vote Democrat, you can't do both. With the advent of abortion politics, you have a BRIGHT line drawn in front of believers. I am an evangelical protestant, so this is easy for me. We were given the example at the Church of Corinth as an example to follow with open sin in the church. I can't understand the other denominations, especially Catholics, that allow the separation of belief's in their denomination. If a person is known to support liberal views, they should be excommunicated. To not do so seems an admission that the church is more concerned with keeping numbers or tithers. How can you preach Sunday after Sunday against something and have pew warmers defy the Word of God? These are not obscure controversial subjects for Christians. I think most preachers would say abortion, sodomy, adultery, lying, and fornication are pretty much black and white subjects. Even Jews surprise me knowing Democrats will turn on Israel and support the terrorists at the drop of a hat.
The religious lines were drawn thousands of years ago. Jesus made it plain that He requires us to follow Him in life after we repent, so these are not new or controversial subjects in church. If you say you are a believer, yet you are still willingly sinning, you are still in rebellion. We all slip and fall, but to even deny sin is sin, is a sign of rebellion. Voting Democrat and claiming Christ is an oxymoron. If the only difference between Democrats and Republicans and Independents was how much the tax rate should be, then we could argue that a Christian could be any political view and still be a believer. When one party wants to remove God from conversation, kill babies, favor sodomy, fornication, adultery, et al, then a Christian MUST flee from said politics. A believer is given the Holy Spirit to be able to discern these things.
PS. Just as an aside, if the Republican party decides to remove certain planks from its platform, Christians will leave it also. We don't vote Republican by default, We vote conservative because Jesus was conservative and His Word requires us to have conservative views. His Word is eternal and never changing.