Not affiliated with any religious group

The new code words for "Muslim terrorist".  I know the reason*, but I'll pose the question for you to think about.  Why does the media insist on speculating that each and every attack is the work of right wing, anti-government radicals with either no evidence or fabricated evidence?  Do you need examples?

• The Boston bombers were quickly speculated to have been motivated by anti-tax and anti-government radicalism, and even when it was discovered who actually perpetrated the attacks, the media tried to paint them as right wing extremists. 
• ABC News immediately tried to connect the Aurora, Colorado shooter, James Holmes, with the Tea Party, finding a completely unrelated person of the same name with Tea Party connections and announcing that fact on their news broadcast.  They hedged their bets by cautioning that they didn't know if it was the same person, but the connection was already there for anyone who wanted to take it.
• After the Gabriella Giffors shooting in 2011 the media, both domestic and foreign, immediately blamed right wing rhetoric for the attacks, conveniently ignoring the fact that most evidence suggested that he was actually very left wing.

Major Nidal Hasan, on the other hand, who killed thirteen people in a shooting spree at the Fort Hood army base, and who shouted Allahu Akhbar while murdering American soldiers, is never referred to as a terrorist. This case is always labeled "workplace violence".

The most recent case to hit the radar (thanks to Small Dead Animals) is that of Terry Loewen, who has been arrested and charged with plotting to use a suicide bomb.

• The BBC announced that he appears to have no affiliation with any religious group
• Charles Cooke tweeted out a comment on Loewen's religious motives, at which point there was a general pile on of leftists claiming that he was clearly motivated by the Tea Party

Unfortunately for the leftist meme, the culprit left some pretty clear evidence of his thought processes for us to ponder:

Once again however, the media and the left will ignore actual or planned violence by the left or by Muslims in order to smear the right and the Tea Party with false accusations.

* The left wing media (ie most of the major newspapers and television networks) are vested in the idea that conservatives (right wing radicals in their parlance) are the greatest danger to civilization.