"...and also that therefore only "universal, rather than religion-specific, values" can be codified into laws in a democracy, with his fellow "progressives" defining which values are "universal" and which are "religion-specific"."

Are you arguing that it is a bad thing to seek out universal values that can guide democracy? If so, are you arguing that "religion-specific" values are the only correct values to be applied in law? Wouldn't that make you a theocrat, and not a believer in democracy?

Since not everyone, indeed most people, do not share your particular religious morality, a truly democratic society would not impose specific religious or cultural ethical systems on its citizens, but would impose a democratic ethical system - that is, a system based on democratic principles only - such as freedom of belief, universal suffrage, equality before the law, etc. That IS what we all agree on, to live in a democracy under a democratic ethic.

If you contradict that by saying we should live under a Christian ethic, not even, a particular sect of Christian ethic, not Liberation Theology, or Deism, or Catholicism, but a peculiar strain of Nationalist Evangelism, then by definition you want a Theocratic state.

The truth is, "progressives" understand that much - they might have a particular social agenda, but at least their arguments are based on democratic principles, whether you agree with them or not; freedom of choice, nonintervention of the state, etc. You might want to rethink the basis of your own arguments: if they're based on Biblical interpretation, then youre not a believer in Democracy.