Tony Abbott is extremely careful selecting some words and yet appears recklessly indifferent when throwing about others.

For example, he avoids the titles Islamic State, or IS, or ISIS, or ISIL.

Here at least, his language is precise and calibrated for purpose.

As a legitimate government leader, he will never extend to the "Daesh death cult" anything that reflects a similar legitimacy.

This quintessence of evil, he believes, must be stopped at source.

Which is why Australian defence forces are the second largest military contributor after the US, bombing targets insurgent in Iraq. And it is why within weeks, Australia will be flying above, and directly hitting targets, in Syria as well.

But when it comes to his political opponents, preciseness in the PM's language is less evident.

Who can forget the "jobs Holocaust" he claimed Labor had presided over, or his labelling of Bill Shorten as the "Dr Goebbels of economic policy" - both slurs quickly withdrawn amid parliamentary uproar.

Withdrawn but not learned from it seems.

Invited by his favourite radio barracker Alan Jones to knock out of the park the suggestion of any electoral advantage from talking up the IS threat, he called it "nonsense". "The latest atrocity apparently was four young men being strung up and burnt alive. I mean, the Nazis did terrible evil but they had a sufficient sense of shame to try to hide it," he said.

There is no argument with his characterisation of the brutal IS, but the usual rule in debating is that mentioning Hitler and Nazis does not strengthen one's argument.

Besides, what was he saying? Yes, the Nazis were bad, but at least they felt bad about it? Their victims and many beyond will be understandably offended.

This pointless foray suggests a Prime Minister more comfortable dividing than uniting.

On election night (two years ago this Monday) he said: "Today, hundreds of thousands of people would have voted for the Liberal and National parties for the first time in their lives ... a good government is one that governs for all Australians. Including those who haven't voted for it."

Fine words, but as Abbott's colleagues weigh their own chances in 2016, some will be noting their PM's unique capacity for abrasiveness, for governing for his cheer squad, and bleeding votes.

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