In the ‘old days’ of the Bush administration, life in a online liberal discussion forum was great. Everybody was having a great time bashing the president and marveling at each other’s brilliance. But in the age of Obama, these once fertile fields of partisan rancor have been tainted by ideological dissent.The latest news from Democratic Underground (DU) is a perfect example of what’s happening to the left online.Earlier this year, the moderators of DU angered users of the forum after they issued a lengthy “censored list” of online behavior that would be banned and deleted from the site. Now, matters...