On his radio show this morning, Glenn Beck, the sometimes incendiary talkshow host, was all sympathy for Sarah Palin. "I know you are feeling the same heat on this," he said, reading out his exchange of email with the firebrand leader who has been accused of helping to create the toxic environment of current American politics.

Forty-eight hours after the massacre at an Arizona Safeway, the left and right were engaged in decrying the violent rhetoric of Obama-age politics while trying at the same time to score points off their political opponents.

Beck used his show to drum up sympathy for Palin, reading out an email from the conservative icon in which she expressed her hatred of violence and those who seek to politicise violence.

He then offered her the services of his own security firm, reading out the name on air. "Please look into protection for your family. An attempt on you can bring the republic down," he said.

Such redirections from the right were typical on a day in which liberal and leftwing commentators sought to demonstrate the connection between rhetoric drenched in guns and violence and political violence, while those on the right sought to deny it.

Some of the exchanges, in print, on television and in the blogosphere, were in themselves an exhibition of the manufactured anger that Clarence Dupnik, the Pima county sheriff, believed was a contributing cause to Saturday's shooting.

New York Times columnist Paul Krugman wrote: "It's the saturation of our political discourse, and especially our airwaves, with eliminationist rhetoric that lies behind the rising tide of violence."

He took exception to the argument raised by some commentators that left and right both engaged in angry rhetoric.

"Where's that toxic rhetoric coming from? Let's not make a false pretence of balance: it's coming, overwhelmingly, from the right," Krugman wrote.

Some on the left had gone even further. Within an hour of Gabrielle Giffords's shooting, the Daily Kos founder Markos Moulitsas had tweeted: "Mission accomplished, Sarah Palin."

But conservative commentators said any attempt to attach political motives to a deranged gunman was unfair ñ or even hypocritical.

"In the Fort Hood shooting, many liberals ignored evidence that the motive was Islamic radicalism and labelled the shooter a lunatic; in Tucson, everything we know suggests the shooter was a lunatic, and yet, they peddle the notion that he was inspired by conservative campaign rhetoric," conservative blogger Jennifer Rubin wrote in the Washington Post.

Over at the rightwing Red State blog, the response to the charges that the rhetoric of the conservative Tea Party movement had demonised the left was delivered with a cartoon depicting the mainstream media as vultures. "Never let a good tragedy go to waste."

The conservative website Daily Caller went further on the offensive, using the massacre to launch an attack on the liberal activist group, MoveOn.org which it described as "having a sordid history of using vitriolic rhetoric".

Others, however, tried to use the shooting as a teachable moment. America has observed other eras of extreme emotion, the liberal commentator EJ Dionne wrote.

"But since President Obama's election, it is incontestable that significant parts of the American far right have adopted a language of revolutionary violence in the name of overthrowing "tyranny", he wrote.

"The point is not to "blame" American conservatism for the actions of a possibly deranged man, especially since the views of Jared Lee Loughner seem so thoroughly confused. But we must now insist with more force than ever that threats of violence no less than violence itself are antithetical to democracy. Violent talk and playacting cannot be part of our political routine. It is not cute or amusing to put crosshairs over a congressional district."

War of words

"He may be a dead man. He can't go home to the west side of Cincinnati ... The Catholics will run him out of town." John Boehner warning of political consequences to a Democratic Congressman who vote for health care bill in an interview on National Review Online 18 March 2010

"I want people in Minnesota to be armed and dangerous on this issue of the energy tax because we need to fight back." Michele Bachmann, Republican member of Congress from Minnesota 23 March 09

"If they bring a knife to the fight, we bring a gun," Barack Obama to a rally in Philadelphia June 14, 2008

"Does sharia law say we can behead Dana Milbank? ...That was a joke." Fox news host Bill O'Reilly 4 Nov 2010