Liberals would tell you that Jesus advocated paying your taxes and helping the poor. They have just as much of a case as conservatives have. Christianity is simply not built on the same principles as American conservatism. There are elements of it that can be used by both sides, but it's a pick-and-choose business.
Pick and choose Christianity? You mean pick from some parts of the scripture and not others? That's not following the Lord, that's following self.
Jesus said "Whoever wants to be my disciple must deny themselves and take up their cross daily and follow me" (Luke 9:23). The Christian must deny their own way and follow Christ and His word. It is not pick and choose.