After more than thirty years of argument about the merits and validity of section 18C of the Racial Discrimination Act, the High Court may finally be asked to answer the constitutional question that has sat unresolved since the Keating government enacted the provision in 1995: can Parliament prohibit race-based political speech merely because it is offensive?

If Hanson seeks special leave, it will be granted. If so, this will become the free speech case Australia has been waiting for.

The facts could not be simpler.

On the day Queen Elizabeth II died, Greens Senator Mehreen Faruqi posted: ‘Condolences to those who knew the Queen. I cannot mourn the leader of a racist empire built on stolen lives, land and wealth of colonised peoples. We are reminded of the urgency of Treaty with First Nations, justice & reparations for British colonies & becoming a republic.’

Pauline Hanson responded: ‘Your attitude appals and disgusts me. When you immigrated to Australia you took every advantage of this country. You took citizenship, bought multiple homes, and a job in parliament. It’s clear you’re not happy, so pack your bags and piss off back to Pakistan.’

Unlike most constitutional law cases, this is immediately accessible. Almost every Australian will instinctively have a reaction. Some will think Senator Faruqi’s attack on the late Queen was gratuitous and offensive. Others will think Senator Hanson’s response crossed a line of decency. Some will dislike both. The tribes will start barracking.

But the legal question is whether parliament may proscribe only one of those tweets. Pauline Hanson’s.

That is why this litigation is so important. While the necessarily technocratic decisions of the Federal Court which have held that Hanson’s breached the Racial Discrimination  Act that led us here are impenetrable even for most lawyers, the factual and ultimate legal questions in this case are disarmingly simple. Every Australian can read those two tweets and form a view. Not of the merits but whether Hanson’s comment should be outlawed. That alone makes it perhaps the greatest civics lesson on the implied freedom of political communication since the doctrine emerged more than thirty years ago.

Remarkably, despite decades of political controversy surrounding section 18C, the High Court has never ruled on whether a law prohibiting specifically race-based speech because it is likely to offend, insult, humiliate or intimidate is compatible with our Constitution. That is astonishing.

The Abbott government tried to repeal the law. Many readers will remember George Brandis’s much-maligned 2014 observation that Australians have ‘a right to be bigots’. It was one of the most misunderstood statements in modern political debate. Brandis was not defending bigotry. He was defending a proposition about liberal democracy: governments should not proscribe political expression merely because it offends.

Not long before that former NSW Chief Justice and ABC chairman Jim Spigelman reached much the same conclusion in his Human Rights Day Oration, observing that there is no right not to be offended. Many of the more progressive – yet old-school black-letter-law – judges back in the day privately thought that 18C was, well, itself quite offensive.

The first instance judgment demonstrated just how critical race theory has infiltrated the minds of some Federal Court Justices. Justice Stewart observed that Senator Faruqi’s description of the British Empire as ‘a racist empire built on stolen lives, land and wealth of colonised peoples’ was not ‘some fringe or revisionist historiography’ and found support in Mabo. Mabo does not really support that.

Fortunately, the full Federal Court shifted the debate back to where it belongs. Unlike Justice Stewart it accepted that 18C imposes a significant burden on political communication. It also accepted that the law chills political speech, and that it was not ‘viewpoint-neutral’. That at least got the case back on track. But to arrive at the conclusion that 18C was nonetheless valid three judges unanimously decided parliament may prohibit some offensive political speech about race because doing so promotes representative democracy.

Say what? Yes. Essentially the full court found that it was open to the parliament to outlaw racist speech on the basis that if it becomes too inflammatory, it may stop some people from engaging in the kinds of debate that are necessary for political debate in a representative democracy.

This is where I part company with the court. Mass immigration, both illegal and legal, that has been occurring across the West is rapidly changing the very foundations of our societies, which means that the current debates about race, immigration, colonial history, multiculturalism and national identity are no longer peripheral political questions. They are among the defining questions confronting every liberal democracy in the Anglosphere. If our constitutional protection of political communication is not at its strongest – which must allow for merely offensive speech – when Australians are debating those issues, then one wonders when it is. The notion that this should be done politely – or at least inoffensively – so that all citizens feels safe to participate doesn’t survive contact with political reality.

Many will say the parliament should simply repeal 18C. Sure, but efforts to do so have not been successful, at least in part because our society has no fundamental understanding of the importance of freedom of speech. This case will generate a public debate that can help to change that.

It is always unwise to predict the outcomes in constitutional law cases. But I will do it this time. If Hanson proceeds with the appeal, the High Court will invalidate 18C. Not because the judges themselves agree with Hanson and certainly not because they approve of the way she expresses herself.  But because if the implied freedom cannot robustly protect political communication on one of the defining issues that representative government now faces, it risks becoming less a constitutional protection than a technocratic constitutional curiosity for legal elites. Then it is not worth all of the trouble the courts and academics have gone to for so long defend its merits and its broader integrity.

After waiting more than thirty years the High Court may soon have the chance to show us whether the implied freedom of political communication in the Constitution is the real deal.