The Australian experience with gun control is as close as you can get to a model demonstration of its effectiveness.

The case is utterly convincing. Here we have two very similar societies, but in one - the US - nothing has been done about mass shooting and in the other - Australia - a vigorous clampdown on guns was imposed.

And the results have been dramatic.

The best thing by far that John Howard did as prime minister was to take on the gun owners after the Port Arthur massacre in May 1996, in which 35 people were killed.

In the 18 years before 1996, Australia had 13 mass shootings with 112 dead. Since then, there have been none. (A mass shooting is where three or more people are killed by an unrelated killer.)

Similarities between the US and Australia abound: frontier societies, hunting traditions, wealth, similar media (including violent videos), and federal systems of government.

But the accursedly misinterpreted Second Amendment to the US constitution, ''the right to bear arms'', has been artfully used to block gun control in the US.

But the constitution is only part of the story. With political will it could be overcome, especially given the recurrent horror of mass shootings.

In Australia in the aftermath of 1996, 700,000 guns were bought by or handed in to the federal government, and destroyed. Checks were made on all people seeking a licence to own a gun and people had to give legitimate reasons for owning one. Self-defence was not a legitimate reason. Later, all handguns were effectively banned.

Immediately, deaths by firearms fell. Suicides by firearm halved from about 500 a year to about 250. Homicides by firearms fell from about 95 a year to about 55.

The Australian Institute of Criminology has done a couple of major studies showing the benefits of the gun reform. The studies factored in generally falling gunshot homicide and suicide rates since the early 1990s, but still found that after the 1996 reforms the rate of the fall doubled.

Significantly, the one area to which the gun controls did not apply - police shootings - did not change after 1996.

In the US, with no such control, the firearm death rate is six times higher than that in Australia.

In the US, 40 per cent of homicides are committed by firearm. In Australia the figure is less than half that rate.

True, the US gun death rate is nowhere near as high as in many Third World countries because poverty begets violence, and poor health systems mean what would be an injury in the developed world becomes a death.

But when you compare the US and Australia, gun laws are virtually the sole point of difference. Men with guns kill people more easily than men without guns. (And they are usually men.)

In 1996, John Howard, only recently elected, spent a lot of political capital getting the gun laws through.

He had vehement opposition from elements in his Coalition partner, the Nationals.

But he showed that these changes can be done and should be done if a nation has a public health problem of this size.

It is also being done in Australia with smoking and road trauma.

But before we get too self-congratulatory and point the finger at the obvious solution for the US, we should recognise the political difficulty of reform and that we experience similar difficulties in Australia in other policy areas.

The gun lobby is very powerful in the US. Its masterful propaganda sways public opinion away from the rational. And its wealth enables it to lobby, skilfully place campaign donations, and propagandise.

It spends $1.06 million a year in direct contributions to key congress members and $2.2 million in lobbying, enough to defeat most gun-control proposals before they even reach the House or Senate floor.

It spends $19 million in advertising and other outside spending - 17th-highest of all US lobby groups - to sway public opinion. Democracy and doing the right thing in the national interest have little hope against such an onslaught.

But Australian politicians can be equally spineless and corrupted. The big miners threw in $20 million to kill a perfectly reasonable tax regime - denying the population as a whole better health, education and other spending.

The clubs and poker machine industry artfully targeted marginal seats in a campaign that destroyed sensible changes to reduce the suffering from problem gambling.

Reform of the junk food industry which is ruining our children's health is also stymied.

The similarity between what happened in Australia with the mining tax, poker machines and junk food and what is happening in the US with gun control is darkly enlightening.

The root cause of this breakdown in democratic process is weak political funding laws.

In the US, the weakness is founded in the free-speech First Amendment (the one just above the right to bear arms). No limits can be placed on the spending of political action committees.

These committees drag in vast sums to propagandise in favour of certain policies and are often little different from campaigning for a given candidate who holds that policy position - usually a conservative. They can stop things being done, resulting in political paralysis.

Coupled with loose party discipline, it means an industry or people with a cause need only target a few congress members to stymie any change.

The weakness in Australia is that disclosure does not come in an easily digestible form. Disclosure of donations should be in a computer-readable form so that you can quickly find out who is getting how much from which industry group and which industry group is targeting which MPs.

Without changes to political-funding rules, sensible changes to gun laws in the US and to poker machines in Australia, and tax in both places, will remain elusive.

www.crispinhull.com.au