R: Obama is the most extreme leftist to ever be President of the US.
D: You are one ignorant, stupid, racist MoFo*
The above sample dialog is probably not the best way to start a mutually enlightening political dialog - unless you consider fist fights to meet that criterion.
Haidt, I think, might suggest a reply more like:
Why would you say that?*MoFo - believed to be an abbreviation for Moss covered Fossil.