Congressional leaders and Members are responding with appropriate horror, grief — and dignity — to the assassination attempt on Rep. Gabrielle Giffords (D-Ariz.) and the killing of her staffer, Gabe Zimmerman, and five others in Tucson.

House leaders postponed debate on the fractious issue of health care reform. Members gathered for a moment of silence on the Capitol steps Monday. There have been prayer services, and a bipartisan resolution of condolence and unity is due to be passed today.

But outside Congress, a climate of rage persists, with conservative and liberal activists both attempting to harness the Arizona shooting for their own political or economic purposes.

We stipulate: There is no evidence whatever that the Tucson shooter, Jared Loughner, was acting under the influence of any particular political movement or ideology. He had a history of mental derangement.

And yet, as Congress mourns, it also ought to reflect on the increasingly toxic political climate in which it works — and resolve, individually and collectively, to make it less rhetorically violent.

We will leave it to scientists and historians to determine whether savagery in speech and imagery directly inspires acts of extreme violence. It’s a disputed matter.

What’s certain is that entire industries have grown up whose business models rely on keeping the public in a state of political frenzy — cable TV channels, radio talk shows, blogs, political consultancies. They exist to make consensus impossible.

Left-wing bloggers accused President George W. Bush of willfully lying to get America into war. Right-wing talk show hosts have accused President Barack Obama of being a traitor, a communist or a Nazi bent on destroying America.

Some Members of Congress and candidates for Congress have sought to capitalize on public frenzy, talking about their supporters being “armed and dangerous,” suggesting “Second Amendment remedies” for America’s problems or firing rifles to demonstrate opposition to unpopular legislation.

Especially during last year’s health care debate and continuing into the fall election campaigns, there was a surge in threats of violence against Members and acts of vandalism at their offices. Both Republicans and Democrats were targeted.

Since the terrible Tucson carnage, elements of the frenzy industry have not had the decency to stand down. Left-wing blogs and columnists have linked the attack to right-wing rhetoric. Michael Lerner of Tikkun magazine said it was “part of a right-wing assault on government and the liberals and progressives who support it.”

And talk show host Rush Limbaugh declared that the Democratic Party “seeks to profit out of murder.” The political left, he said, “is depraved, empty, without any substance whatever.”

It’s impossible for Members of Congress to totally ignore this rhetoric. It affects their constituents, and their constituents influence them. But they can try to rise above this wretched din, try to limit its effects and act as principled agents of their country’s well-being.

We urgently hope that, out of enduring respect for Giffords and Zimmerman, Members will heed her wish, expressed recently in an e-mail to a Republican friend, to “tone our rhetoric and partisanship down.”