In my mind, the trick to keeping things civil is knowing what to discuss. Avoid political hot buttons such as Obama/Romney/Obamacare. Instead talk about bigger issues, such as what should be the role of the government in creating opportunities for people to thrive, or what is a good level of economic inequality in our society? In terms of religion, abortion might be a good hot button issue to avoid depending on the audience. Instead, discussions about the bigger issues can range from exploring what should be the roles and limits to religious involvement in politics (and visa-versa), to what people think is the nature of God (no right or wrong answers here).
To quote Jensen:
Remember this: Our affluent society produces an excess of everything except what we most desperately crave: meaning. Such meaning comes when in our everyday lives we talk with people - those we know and strangers on the bus - about the most basic questions that have unsettled humans forever: What does it mean to be a decent human being? How do we deal with the problems of power?The full article is available at: http://www.statesman.com/news/news/opinion/jensen-go-ahead-talk-religion-and-politics-at-the-/nS9zg/