In this article from Ilene Wasserman on Entrepreneur.com, the focus is more on how to properly engage a co-worker in a political discussion. Her ideas are sound.
But as a manager, the easiest way to avoid confrontation and difficult feelings is simply not to discuss politics – or sex, or religion – with your employees.
Keep your workplace a forum for business ideas and discussions, and not a political forum for your own (or others’) beliefs.