Moynihan was a prominent Democrat for 15-20 years. Whether you agreed with him or not he was always willing to sit down and have an intelligent discussion on most any subject. People forget there was a time in this country where people would actually listen to each other while making their case on any particular subject. There would be an equal exchange of ideas.
Always big on Socialism, Moynihan was well known for doing his homework. Unlike today where politicians throw grenades such as calling the other side racists and terrorists, Moynihan knew both the history and the statistical numbers behind his ideas.
And here's the kicker - he would also point out the inherent Catch 22 of various Big Government programs, many of which he supported. As such Moynihan would essentially argue both sides of an idea. "Yes, we need this government program but we need to be careful of its consequences", would be a typical Moynihan approach. Instead of simply throwing money at a problem he would think it through several steps down the road.
It's a rotten shame the days are long gone where both sides can sit down and have an equal exchange of ideas.