ABC News (online)
By Brigid Andersen
The shooting of a US congresswoman and 18 other people at a shopping centre in Arizona has brought back memories of the 1995 Oklahoma City bombing.
On Saturday, a lone gunman walked up to congresswoman Gabrielle Giffords and shot her in the head while she was holding a public meeting at a Tuscon supermarket.
In a matter of minutes, six people were shot dead, including a federal court judge and nine-year-old girl. Ms Giffords remains in a critical condition in hospital.
The shooting comes in the midst of an almost toxic political environment in the United States, particularly in the state of Arizona.
And while the attack has not been labelled home-grown terrorism, it has stirred memories of such an event.
Associate Professor Brendon O'Connor from the University of Sydney's US Studies Centre says the shooting and the political environment echoes that around the time of the Oklahoma bombing.
"The best recent parallel was in 1995 with the Oklahoma City bombings of April that year when Timothy McVeigh - who was one of these extremely anti-government people - blew up a federal government building and I think about 165 people were killed," he said.
"That was a tragedy and in many regards, there was a pulling back after that event, as Bill Clinton talked at the time about the need for a much more civil way of talking about government and really calling upon his opponents to tone down some of their anti-government rhetoric."
Fierce political debate has broken out in the wake of the weekend's shooting, but for over a year the atmosphere in American politics has been explosive.
The rise of the conservative Tea Party movement in response to US government bailouts and taxes has seen an increase in angry public rallies and the use of violent imagery.
Professor O'Connor says the inflammatory nature of US politics is concerning.
"What I'm most concerned about is the anti-government rhetoric," he said.
"If you continually suggest that your government is corrupt or illegitimate or that your government is trying to take over your life ... then there are unfortunately people that take this incendiary language much more to heart, much more seriously, much more maybe psychically in the case of this gunman."
In the crosshairs
The spotlight has fallen on a campaign website for Republican and Tea Party darling, Sarah Palin, that put rifle crosshairs over several congressional districts, including that of Ms Giffords, and urged voters to "reload".
But Professor O'Connor says such violent imagery is not exclusively used by Republicans.
"The use of firearms, gun imagery, runs pretty deep in American culture," he said.
"The candidate who just won the senate seat in West Virginia - a Democrat - one of the ads he had was him loading a shotgun or a rifle and shooting at a target, which was policy to address global warming."
"It's not exclusively a Tea Party or a Republican thing, but I think on the conservative or on the right side of politics it's more commonplace."
Professor O'Connor says these types of messages have inflamed tensions, particularly in Arizona.
He points to comments from the sheriff investigating the Tuscon shooting.
"Comment by the sheriff in Arizona that really there is a climate of hatred in Arizona, things have really just become toxic politically," he said.
"I think he's tapped into something and for whatever reason he's felt that on the ground.
"That really goes into a background of Arizona last year, being the site of a lot of controversy regarding policies to do with illegal immigrants, a policy which allows people to have their ID checked randomly on the streets if they look like an illegal immigrant."
Conservatives have been quick to blame the weekend shooting on the actions of a deranged individual, but some Democrats pointed to the escalation in violent political rhetoric.
Professor O'Connor says it would be unwise for the Democrats to start piling the blame on the right of government.
"I think that the Democrats would be more sensible to say look, 'this isn't helpful, we understand that there are unfortunately deranged people in our society but there are also some issues, there is this issue of gun control', I think you might want to put on the table as well," he said.
He says similarly to Mr Clinton's actions in the wake of the Oklahama bombing, there is now likely to be a pulling back in American politics.
"I'd say, we'll see quite a lot of soul searching in the US," he said.
"I think, there will be a sense that some of the language has been over the top, irresponsible and that there will be a need for a much more civil conversation about the people who represent the US doing a good job, but sometimes, obviously like in all policies you have disagreements of opinion."