Today POLITICO Arena asks:

Post-Tucson will campaign trail rhetoric change in any discernible way? Should it change? What phrases or words should be considered out of bounds? Or is that approach a way of silencing legitimate criticism of political candidates?

My response:

Post-Tucson campaign trail rhetoric won’t change because, as Charles Krauthammer put it brilliantly in yesterday’s Washington Post, fighting and warfare are routine political metaphors for obvious reasons: “Historically speaking, all democratic politics is a sublimation of the ancient route to power – military conquest. That’s why the language persists,” why we speak of “battleground states” or “targeting” opponents.

That doesn’t mean that no charge is “out of bounds.” It’s perfectly all right for Sarah Palin to “target” 20 potential swing districts – Democrats do the same. And her use yesterday of “blood libel,” as Alan Dershowitz explains, is entirely acceptable too. What is out of bounds is the kind of scurrilous charges we’ve seen from The New York Times, the Paul Krugmans, E.J. Dionnes, Jonathan Alters, and their ilk, that the Tea Party and the political discourse around it contributed to the Arizona shooting – when there isn’t a shred of evidence to support that, and every indication that a lone mentally disturbed individual was responsible.

But far deeper issues are at play here, and they’re brought out in a penetrating piece by Daniel Henninger in this morning’s Wall Street Journal, “Why the Left Lost It.” He points first to the devastating, potentially sea-changing midterm elections – “Republicans now control more state legislative seats than any time since 1928” – which “came atop the birth of a genuine reform movement, the tea parties.” And the debt crises, state and federal, that animate the Tea Party pose a mortal threat to a liberal agenda that stretches back at least to Goldwater.

As Henninger writes, the divide between today’s left and its conservative opponents “is deep, and it will never be bridged. It is cultural, and it explains more than anything the ‘intensity’ that exists now between these two competing camps.” Read it.