Australian newspaper front pages on March 16 show coverage of the attack in Christchurch. (James Gourley/Getty Images)

Why does it seem so hard for people to grasp the connection between hate-filled speech and hate-filled violence? The alleged attacker who carried out Friday’s massacre in Christchurch, New Zealand, was acting on a toxic belief system — one that has been long nurtured by opportunists in politics and the media, in Australia and elsewhere.

Those innocent victims — the toll now stands at 50 — reaped what others had sowed.

The alleged gunman, a 28-year-old Australian, saturated himself in the verbal violence of Islamophobia and white supremacy. His manifesto name-checks figures from outside Australia: people such as the United States’ Candace Owens and Norway’s murderous Anders Breivik.

But there are also those at home who’ve created the soil to nourish violence.

Last August, a Queensland senator, Fraser Anning, used his first speech to Parliament to call for a return to a “European Christian” immigration system and a ban on Muslims migrating to Australia, even managing to work in the repulsive phrase “final solution.”

He was condemned, but he’s still in Parliament. In the hours after the Christchurch attack, he used his parliamentary letterhead to present his response, essentially blaming the victims for their own deaths.

In its general programming, Sky News Australia has turned into our version of Fox News. (Both are controlled by the Australian-turned-American media baron Rupert Murdoch.) Sky’s attention-seeking programming even included an interview last year with Blair Cottrell, a Hitler-admiring, far-right extremist who had been found guilty of inciting contempt, revulsion or ridicule of Muslims.

In a Murdoch-owned tabloid in Melbourne, prominent columnist Andrew Bolt has written of “us” disappearing as “a tidal wave of immigrants sweeps away what’s left of our national identity.”

Meanwhile, the politician in charge of immigration, Peter Dutton, has seized on criminal behavior by some young immigrants in Melbourne to condemn a wave of “African gang violence” so severe that Victorians were “scared to go out to restaurants” — a statement that was widely mocked.

It was also Dutton who suggested Australia should provide special help to white farmers from South Africa — arguing that they were being persecuted and needed help from a “civilized country” like Australia.

The Australian media and politicians, in other words, have form when it comes to flirting with racism. Sometimes the racism is explicit, as seen in the rise of Pauline Hanson’s One Nation; sometimes it’s more guarded.

The term “dog-whistle politics” may be widely used in the United States, but it has become ubiquitous here — so perfectly capturing what has become a common technique. The politician chooses his words carefully, avoiding explicit racism, but crafting a message that will still be heard by those for whom it’s intended.

And so “border control” becomes code for keeping out Muslims, and “equality for all Australians” means stripping services from indigenous communities.

Just recently, we saw a debate over legislation that will allow doctors to provide medical care in Australia to refugees currently held offshore. The bill was carefully worded and limited in scope, yet it brought furious criticism from those who said the arrival of the asylum seekers would so burden the local health system that some sick Australians would be refused care.

Who would make such exaggerated claims? A fringe politician? A radio host in search of an audience? No. The claim was made by Prime Minister Scott Morrison, backing up similar comments from Dutton.

Some even accuse Morrison of advocating the use of anti-Islamic rhetoric as a vote winner back in 2010. Alongside a preference for baseball caps, this is something he may share with President Trump.

National elections in Australia have been won by the exploitation of anti-immigration anxiety.

We have another election campaign looming — probably in mid to late May. The two major parties enter the campaign with starkly different policies on climate change, the minimum wage and how to tax some investment income.

Is it too much to hope that, this time around — with so many legitimate policy differences over which to tussle — we can put aside the anxieties over asylum seekers, Islam and “African gangs”?

In the shadow of Christchurch, it’s the least we can demand from our political class.

Read more:

It’s time for Australia and New Zealand to confront their white nationalist histories

Jennifer Rubin: Demonizing Muslims and immigrants leads to predictable results

Max Boot: Not all terrorism is treated equally

Elizabeth Bruenig: The New Zealand attack and the fundamental thoughtlessness of evil