There are really two ditches that churches fall into when it comes to entering into and challenging the political climate—and culture, generally:
Some churches are tempted to think, “Jesus is gone, it’s all on us.” It’s not that activism itself is wrong, but it becomes unrighteous when it’s done without God’s strength. It becomes unrighteous when sin is reduced to corporate injustice. Sometimes the theology of these churches is more like deism. God’s there, but he’s not real helpful. “Thanks for creating the world. We appreciate some of these inspirational verses, but we’ve got it.” These “liberal” churches are really good at entering into culture, but they can easily jump into the prevailing stream without considering how the Bible might offer some critique.
“Conservative” churches fall into this. For the most part, the attitude is something like this: “Jesus is gone, but he’s coming back, so we just have to sit here and wait it out.” This is how the whole evangelical subculture happens with it’s own t-shirts and breath mints (Google “testamints”). “We’re going to do our own thing, and hide from the big bad world.” These churches can give the impression that sin is something “out there,” and as long as interaction with the world is limited, you’ll be safe.
These ditches are why the church has lost a lot of influence.