Influence over the "unhinged"

Popular buzzwords this week in the wake of the Tucson tragedy.

• Violence
• Vitriol
• Unhinged
• Rhetoric
• Media
• Despicable

I have a simple question.  If the argument is that political rhetoric influenced the "unhinged" fringe, mentally unstable portion of our society, then shouldn't there be a reasonable connection with them watching, or obsessing with exactly that speech?

I've heard many a media commentator claim that it just intuitive, common sense, to make that connection even though it can't be proven.

Seems to me, that if we are making that argument, then the connection to the movies, and entertainment forms of all types is a far more likely channel for such a connection.

Why would speech by political leaders be somehow more influential?  than video games: World of Warcraft, Call of Duty Black Ops, Battlefield... Movies from Inception, and the Matrix, Bad Boys, to Sniper, and even James Bond... where solutions are always at the end of a gun or some explosion.
My common sense, intuition is that the volume of media espousing violence in the entertainment industries is a more likely candidate for influence over the unhinged, mentally unstable citizens of our great country.

That said,  I still wouldn't support further regulation of any of this free speech.  The accountability lies with the "actor" of the atrocity, not the society or the media.

“We must reject the idea that every time a law’s broken, society is guilty rather than the lawbreaker. It is time to restore the American precept that each individual is accountable for his actions.” ~ Ronald Reagan