When it comes to blaming the media, America’s political classes play a peculiar kind of game — one that periodically sees them switching sides.

The assassination attempt on Arizona Rep. Gabrielle Giffords that killed six people and left Giffords critically wounded yielded intense speculation about the cause of those events, and whether inflammatory rhetoric from right-wing media played a role. Voices on the right quickly raised the barricades, insisting that only a deranged mind would engage in such violence, and that blaming talkradio or cable news amounted to politically motivated attacks.

If that sounds familiar, it should. But in the context of TV sex and violence or incendiary music — and what can be attributed to pop-culture images and ideas bombarding youths — the political affiliations have often been reversed.

What’s most interesting is that neither side appears to recognize how its position in one case undermines its stance in the other. Or perhaps being consistent about the nebulous relationship between cause and effect pertaining to media is simply too inconvenient.

For years, politicians on both sides of the aisle have assailed the TV and movie industry for their work’s collateral damage, leaving Hollywood’s famously liberal creative community to defend itself with the argument that people (especially those armed with guns) kill people, not episodic TV, provocative lyrics and horror films.

While the right has inveighed most vigorously against sex, high-profile liberals have frequently been the most outspoken advocates regarding media violence. Tipper Gore led the charge against music, lobbying for warning labels on explicit material. Then-Sen. Hillary Rodham Clinton campaigned against violent videogames, and her husband famously had his “Sista Souljah” moment, when he denounced a rap artist.

“We know that violent videogames have an impact on children,” Hillary Clinton said in 2005, adding that while various factors affect juvenile crime, “What the research tells us is that for individual kids, violent media is harmful.”

When such blame falls on media, one seldom hears the political right — with its antipathy toward Hollywood — marshal a defense like the one mounted in the wake of the Giffords shooting. Instead, the logic tends to resemble that employed by Sarah Palin in her Jan. 12 video statement, in which she indignantly said that while her words couldn’t possibly lead to violence, criticism leveled against her by liberals “serves only to incite the very hatred and violence they purport to condemn.”

With innumerable studies about a correlation between media and actual violence dating back to TV’s infancy, tubthumping this link has always felt like a facile political tool. Why tackle a political hot potato like gun control, after all, when we can appear to be doing something by going after “Gunsmoke?”

The bottom line is that the gap between correlation and causation — as well as ethical factors that prohibit real-world experiments — forces serious research to hedge its conclusions. And with so many variables to consider, connecting such an event to a single triggering mechanism — however heinous — risks grossly oversimplifying reality.

Not that this slows down the media’s hunger for clarity — for heroes and villains — amid the heat of breaking news. As New York Times columnist David Brooks put it, “We have a news media that is psychologically ill-informed and politically inflamed.”

“The Daily Show’s” Jon Stewart — who staged a rally intended to “restore sanity” — registered a similar point, more eloquently, in his first program following the Giffords shooting.

“We live in a complex ecosystem of influences and motivations, and I wouldn’t blame our political rhetoric any more than I would blame heavy metal music for Columbine,” he said, adding, “Boy would it be nice to be able to draw a straight line of causation from this horror to something tangible, because then we could convince ourselves that if we just stopped this, the horrors would end.”

Assigning blame is comforting, and those doing so invariably choose ostentatious targets with an intuitive kernel of truth.

Is some rap and heavy metal offensive? Undoubtedly. Has talkradio coarsened political discourse? It’s difficult to argue it hasn’t.

Yet it’s a vast leap — indeed, in practical scientific terms, a near-impossible one — from something being distasteful to establishing a clear-cut cause-and-effect.

Still, Skeptics magazine publisher Michael Shermer said such connect-the-dots exercises are part of human nature.

“Patternicity is what our brains do,” he wrote in the Los Angeles Times, citing a natural tendency to “seek out deep causal meaning in some grand, overarching theory.”

In that context, the pattern since Arizona has been painfully familiar: Tragedy, followed by a knee-jerk reaction, and then a retaliatory response. And eventually, a collective bout of amnesia until the next crisis — and another opportunity to play the blame game.