There is a double standard at play, but we already know that. It's when they start exploiting a heinous massacre for partisan purposes before emergency personnel can even arrive on the scene (and before anyone even knows any facts) that it becomes truly screwed up.
This is true. There's no proof that Loughner was right wing or particularly interested in politics. But notice how people have made the connection between the shooting and the rhetoric we've heard the past few years. Doesn't that suggest something's wrong? And both sides are to blame.
One thing we can take from this: In the end, it doesn't matter what Loughner's politics were, what matters is we recognize that violence doesn't work, gets us no where, and disgusts all of us. That includes violent words. It's time for both sides to calm down, shut up, and start listening. I'm interested to see who actually does that.