I have not found very many instances where intellectual debate stirs positive results. Recently California had a ballot measure that would legalize marijuana. The only reason this ballot lost was not because people didn't like the idea (overwhelming amount of people supported it). The reason it didn't pass was because propaganda won out by making people believe that the bill would allow people to drive/work stoned.
In this, it is not debate that has won, but fear mongering.
Please name me one country where people are being machine gunned for simply debating politics. Actually, better yet, don't reply. I don't want this board being cluttered up with nonsensical rhetoric.
The biggest problem with debating politics I find, is that people are more ingrained in group think than anything else. People proactively identify themselves as liberals, conservatives, "values" voters, etc. The thing that has made debating politics useless is that the opinions of the people you debate with aren't really their own. They belong to a group, whose ideologies they adopt wholesale.
In a recent interview, Justin Bieber said that Canada had better healthcare than the US, and that abortion is murder. This pissed off conservatives and liberals. Based on these opinions however, is Justin Bieber a "conservative" or a "liberal"? Because to me, he sounds like a person who has his own opinions.