I think I understand where the animosity comes from. The readiness to go for the cheap shot or the personal attack, just because someone disagrees.
The state of political discourse on this site is just a reflection of the sad state our nations political discourse is in.
The extreme right and left in this country espouses their respective ideologies in such a way as there is no room for compromise and those 'moderates' that do seek consensus and compromise are labeled as spineless, wishy washy or perhaps traitors to their party and/or country.
The contempt people have for certain political figures and political ideologies, often fueled by whichever political commentator/s they most identify with, bleeds over into their discourse and they project that contempt onto those who disagree with them and their chosen ideology.
I don't have a fix for it, I don't think people can be depended on to 'self moderate,' at least when it comes to discussing politics. They take it personally, to much of what makes up their whole world view is invested in their political ideology. An attack on their deep held political beliefs is perceived as an attack on them and they take it just as personally as if someone attacked their religious beliefs.
Do I think I'm above it all and somehow immune to this syndrome? Not hardly, I've been guilty of attacking others for their opinions or what they thought of mine, on several occasions.
In closing I would like to say that I enjoyed the L&P section and the spirited debates we had there, I wish it didn't have to change or go away, but I don't know a method to force civility on people as they discuss contentious political topics.
"No free man shall ever be debarred the use of arms."- Thomas Jefferson