When it’s all over, Barnaby Joyce’s clearest contribution to Australian public life will likely be a rule that says ministers cannot have sex with their staff. The second most senior member of this government – the deputy prime minister – is a politician whose talents add up to a total of nothing.

Joyce is an emblem of all that is wrong with modern politics: hubristic and self-interested, a joke in search of a punchline.

This is the man whose most important speech in office related to whether or not he would kill Amber Heard’s Yorkshire terriers. The man who, awaiting the outcome of the United States election, told a journalist: “Somebody sent this letter to my office today. It ran like this: ‘I don’t know who’s a bigger cunt, you or Trump. But I think you win.’ ”

This is the man who, as shadow finance minister, looked at the national debt and said, “All this billions, quillions, Brazilians, whatever you want to call them, they’re just numbers.” He is the man who, more than any other, is destroying the environmental flows of this country’s rivers.

Joyce’s is a career untouched by competence. He treats his portfolio as an entertainment, a curiosity out of which he has learnt to coax various amusements. The greatest marker of his time in politics is his red-faced hypocrisy.

In 2013, Joyce discussed replacing welfare payments with food vouchers for people who break the law. “People who are on social security and make other people’s lives difficult should be punished,” he said. “The fact is that other people go to work for that money, and these people show no respect for that.” Joyce has brutal contempt for those without money. His apparent farm boy authenticity does not belie an egalitarian but rather a buffoon. His values are not of grit and hardship but the boarders’ college at Riverview.

In April last year, he demanded young Australians “damn well get off your backsides” and take jobs wherever they may be. A month earlier, he had argued for changes to privacy laws as they pertained to welfare recipients. The government wanted the right to release the information of individuals who criticised its social security policies.

“Barnaby, let me get this straight,” he was asked. “You’ve got no problem at all with the government leaking people’s private information to win an argument. Is that right?”

His irritated response? “If you want to keep your information absolutely private, don’t go and get the dole whilst you’ve also got a job.”

Joyce’s thoughts on entitlement, rights and responsibilities are useful in the context of his actions this week. They are but a small example of how pathetic, how pointless and unrewarding his legacy will be.

It is Joyce who was paid a salary by his party during his period of parliamentary ineligibility – even though that ineligibility was owing to his own gross negligence. It is Joyce who will continue to collect his salary next week, despite his obvious inability to acquit the duties of that salary.

It is Joyce who deceived his family over his affair with a staffer, at the same time as he forced the country through a national debate on the legitimacy of same-sex relationships. It is Joyce who argues for every draconian intervention in the lives of welfare recipients, while at the same time jerry-rigging the definition of “partner” so the woman now carrying his child might subsist on a salary of almost $200,000.

There is no suggestion that any of this breaks the law, or even the ministerial code of conduct. Like taking a helicopter to a party fundraiser or asking a hostile government to pay for travel, however, it is rotten with entitlement.

For what now seems an interminable period, parliament has bred rancour, dysfunction, incompetence, indecision and scandal. Its legislative record is ever diminishing. Its claims to vision or leaderships are increasingly tenuous.

Barnaby Joyce is a disgrace. He has not the talents to warrant a place in the parliament, much less the ethics – and that makes him not very different to many of his colleagues.