They have bemoaned the state of America's political discourse, called for leadership in toning down heated rhetoric, speculated over whether this is a turning point for Barack Obama or Sarah Palin and puzzled over the shooter's mental state.
But one thing that has scarcely been raised is gun control.
In Australia, a 1996 gun massacre in Tasmania promoted a deeply conservative federal government to push for restrictive gun laws.
But here in the US, the only regulatory response so far has been to call for a ban on the sale of high capacity magazines like the sort that Jared Loughner allegedly used in Arizona, enabling him to shoot 31 bullets from a semi-automatic handgun without having to reload.
Two possible bills proposing such changes are unlikely to pass the Republican-controlled House of Representatives.
Many in the US believe the situation would have been safer if more people on the scene had had guns. At least one congressman has now said he will start carrying his gun at all times.
The Arizona Citizen's Defense League is calling for members of Congress and their staff to receive firearms training.
Such responses leave many in other developed democracies scratching their heads, asking the same question: what is it with America and guns?
America's love affair with the gun is steeped in the nation's foundational stories, particularly its history as a frontier society without an established military.
"The threat of French, Spanish and Indian hostility on the frontier meant that from the very beginning America was a society that relied very heavily on a population that is armed," Saul Cornell, an American history professor at Fordham University in New York, told the BBC.
"Basically we had a militia as the organisational building block of internal and external defence."
Jan Dizard, who teaches American culture at Amherst University, adds that Americans have a long history of sanctifying all that is associated culturally with "winning the west" and beating back Britain.
"The myth of the frontier, the myth of the individual defending him or herself against bad guys that the state is unwilling or unable to protect them from runs very, very deep," Mr Dizard, a gun-owner and hunter himself, said in an interview.
Over time, gun ownership has become fused with a particular brand of American identity that prizes rugged individuality and libertarian notions of freedom - mostly freedom from government.
Daniel Webster, a director at the Johns Hopkins Center for Gun Policy and Research, says American individualism explains why the immediate response to shootings like the Tucson tragedy or the Virginia Tech massacre is not to look for legislative remedies.
"An important thing to understand about American culture is that we tend to place responsibility and focus on individual behaviour rather than think about laws and regulations to affect behaviour," he told the BBC.
Mr Webster says that it is common for people simply not to ask why guns are so prevalent or why mentally unstable people can so easily access them.
Instead, he says, their attention focuses on what was wrong with the individual shooter. Did he have a troubled past or a mental illness?
"Our responses tend to be ones in which we punish the offender and try to enable individuals to protect themselves. But we are reluctant to act collectively to make our communities and our country safer," he said.
Over the years there have been attempts to curb gun access. But they have mostly been marginal.
In the 1930s, the National Firearms Act banned sawn-off shotguns, which had become popular with the mob during prohibition.
After the assassination of President John F Kennedy, the purchase of guns through the mail - which is how Lee Harvey Oswald bought his weapon - was outlawed.
In 1993, President Bill Clinton signed the Brady Bill, which required background checks for buyers of firearms at licensed dealers and had been backed by President Ronald Reagan. The next year, Mr Clinton successfully pushed for a ban on assault weapons.
That bill expired in 2004 but, had it still been in place, the Arizona gunman would not have been able to purchase the high capacity magazine he used on Saturday.
Surveys suggest the majority of Americans do actually support many of these measures, while opposing outright weapons bans.
The National Opinion Research Center found in 2007 that 82% of those surveyed supported a ban on assault weapons, while CNN found that 79% of Americans favoured requiring gun owners to register their guns with local authorities.
Most gun control advocates point the finger at the National Rifle Association (NRA) for stymieing the political will in Congress to act.
The NRA has a large, extremely well-funded political lobbying operation - deeply supported by weapons manufacturers - that will not brook any infringement on the constitutional right to bear arms.
For the NRA, that means no limits on access to high-powered weapons, no limits on the number of guns an individual can purchase, no waiting periods for prospective gun owners, and so on.
The organisation has an enormous capacity to run political ads for and against candidates, based on their gun politics.
Mr Cornell says that it also has a very loyal core of members who care about firearm freedom above all else. Passions mostly run higher among the gun owners than the regulators.
"They demonise their opponents and whip their base into a frenzy about this issue. They bring up all these fears and anxieties about safety and government. How are the voices of reason and moderation supposed to battle that kind of opposition?" he asks.
The NRA has not yet responded to BBC requests for a comment.
Mr Webster adds that the US political structure militates against stronger gun laws. Suspicion of central government has meant much of the authority to regulate guns has been devolved to the states.
And in the US Senate, sparsely-populated rural states like Montana, Idaho and North Dakota - states where gun access is especially prized - have the same political power as heavily urbanised states like New York and California, which tend to be more supportive of regulation.
So, even after the horrifying events of Tucson, the sum of all these factors - frontier history, an individualistic society, a potent gun lobby and powerful rural states - most likely equals business as usual for US gun owners.