I believe if you are too far right or too far left then it would be difficult. Those of us who hover somewhere in the middle but connect with either Democratic or Republican beliefs can easily do this. Issues are not as black and white to us.
When dh and I were younger we were both in the middle, I have remained but dh has been moving right for years. It does make it very hard to discuss certain issues with him, so I don't. He knows where I stand so we have an unspoken rule about what we will talk about. The problem comes when he feels he needs to rant about something and I'm the only one there to listen.
When it comes to our family and our moral values we are on the same page, if not we wouldn't be married.