I'm not entirely sure that you CAN have something like a church congregation without some "glue" for social cohesion. I don't think that "Just be nice" is sufficient. Whether it's a shared dogma, or some shared activity, or (perhaps most effective of all) a shared enemy... groups seem to need a strong purpose in order to endure over the long-haul.
The US two party system provides a far-right choice and an ultra-extremist-right choice. This is a little too international for some to handle, or you can think about it as they're not modifying their message to fit local culture, which probably doesn't help recruitment.
Its a big world, and the sermons posted on the local church website here, might have little appeal to the attendees of your local church.
From the transcript of the MLK sermon at my local UU church:
"We just heard words from Dr. King, “Injustice anywhere is a threat to justice everywhere. We are caught in an inescapable network of mutuality, tied in a single garment of destiny.” I have always found a profound parallel between that quote and the seventh principle of the Unitarian Universalist Association – that we affirm and promote respect for the interdependent web of all life, of which we are a part. Sighing with relief because I am not being treated unjustly is not an adequate response for a Unitarian Universalist when so many are forced to go without what they need."
Its not exactly "workers of the world unite" or "eat the rich", then again its not the contemporary "Christian" message of "let them eat cake".
I admit I am intensely biased, if I were legally forced to join / attend a church it would almost certainly be this one.