Can someone give me a super layman's explanation? I always thought Liberals Christians don't view the bible as authoritative, and morals align with political liberals?
Hedrick has the best explanation around from an academic standpoint.
The best explanation I would give is that liberal Christians are intellectually critical when it comes to theology, and more individualistic when it comes to discussing ethics and morality.
I wouldn't say liberals see no authority in the Bible, but this authority is handled through the critical methods of theology. If a Bible passage appears to command stoning adulterers, for instance, we aren't going to automatically assume that's the right thing for us to do.
If you are Protestant, you automatically share some things in common with some liberal Christians, since Protestantism is basically a product of liberal humanism in the late renaissance. The idea that anybody can read the Bible apart from church tradition or a confessional community is even quite radical, even from a liberal/Progressive Christian viewpoint, and it is something that some mainline Protestant traditions have backed away from. Esp. because dogmatic adherence to this idea (the perspecuity and clarity of Scriptures) lead to religious wars in Europe that were some of the most bloody in history prior to the 20th century. So a moderate liberalism emerged from that, especially influenced by the Enlightenment, that relied less upon dogmatic claims and more upon higher criticism, reason, and experience. In short, liberal Christians do not believe the Bible is necessarily a clear window into God's mind or will, except in a limited sense. When people disagree, it doesn't automatically make the other person wrong, because we admit that the Bible is difficult to understand exhaustively.
Here on CF "liberal/progressive Christian" seems to be an umbrella of different ways of being Christian. There's a statement of purpose sticky at the top of the forum that talks about what makes Whosoever Will, May Come different from moderate or conservative subforums.