What Does It Mean to Be Prophetic?

I stumbled across a post by Methodist blogger Allan Bevere on the prophetic nature of the church.  He ends to post like this:

As I continue to say-- when Christians hear the word "politics" they should not think state; they should think church. For Christians, our politic is church. But that clearly is not what it has been and both the Christian right and the left are guilty of making the church somehow beside the point. Because we have reduced the "political" to partisan politics we have reduced the church to one more social agency and one more culturally acceptable option to choose from-- like the having season tickets for the local sports team and a membership in the zoological society-- though we are actually more excited about going to the ballgame than being an ecclesially based new society.

As Stanley Hauerwas has prophetically said, "in the name of being politically responsible, the church became politically invisible."

Which has led me to ask this question: what does it mean to be prophetic?  The reason I ask is that I think a lot of folks have an idea what it means to be prophetic that I think is a bit wrong.  I will see a pastor who will get up and talk about some of the major issues facing our world and it is billed as "prophetic."  But more often than not, what I hear is more of a political agenda than it is calling the church to present the Kingdom of God.  Since I move around mainline/progressive Christian circles, I tend to hear what sounds like a churchified version of the Democratic party platform, but I'm pretty sure that a lot of what might pass as prophetic in evangelical circles just mirrors the GOP agenda.

So, what does it mean to be prophetic?  What does a prophetic church look like?  I have to think that it's more than a party platform sprinkled with lots of Jesus.  I'd like to know, because what I see passing as prophetic kind of falls short.