Nearly a fortnight down the track, a grim Tony Abbott is selling his budget. The flesh is pared from his bones. He is speaking at walking pace. His temper is in check. Retailing his broken promises is only part of the prime minister’s task. More profound is the challenge he faces persuading Australians they haven’t elected a stranger.

Where in the narrative of Abbott’s life does this budget come from? Where is the man who once talked of his commitment to the poor, to the austere charity of the old DLP? Where is the politician who had the courage to warn John Howard that WorkChoices was a dog? Where is the campaigner who looked Australia in the eye and promised never to tell a lie?

Politicians shift and change. They must. Selling those shifts is a key political skill. Abbott just moves on. The ruthless boy scout of opposition has turned into the dour fibber of government. He blames Labor. But this week’s terrible polling figures suggest the nation is now more wary than ever of the man we elected.

What’s oddly disturbing about Tony Abbott – and has been all his career – are the shifts and changes of tack. There’s a sense that there is no through line to the narrative except the pursuit of power. The Abbott we see at any particular moment seems only the Abbott that’s necessary for now. Another shift is always on the cards.

Abbott the minister for health in the Howard government floated the idea that Canberra should take over the hospitals of the nation. The party, the cabinet and the bureaucracy were appalled. He went even further in his 2009 manifesto Battlelines, calling for Canberra to be given all power in all fields in order that the national “government can call the shots”.

But Abbott PM has brought down a budget that slashes health and education funding in order that each state be “sovereign in its own sphere”. This is not a small shift. Very different ideas of Australia are involved. So what’s the narrative here? How has the Abbott of 2009 morphed into the Abbott of today? He offers no explanation. He just presents himself as a different man for a different purpose and another time.

All his life he has been producing these fresh versions of himself. Gone now are the loudmouth bigot of his university days, the homophobe, the Rhodes Scholar, the Mad Monk, the Labor voter. He’s done a lot of growing up. He’s read and thought. He’s married and had children. But the many transformations of Tony Abbott have been driven less by the enduring values he boasts than the ambitions he has always pursued.

"The Abbott we see at any particular moment seems only the Abbott that's necessary for now. Another shift is always on the cards."

Keen to enter politics after abandoning the seminary, he tried to persuade his old mentor Bob Santamaria to lead the remnants of the DLP back into the Labor Party. He wrote: “Our roots and the origins of our political culture are there.” But Santamaria directed him to the Liberals. John Howard talked the young man across. He joined the party in 1988 and after brilliant work promoting the monarchist cause was in parliament by 1993.

His opponents in the party thought him a Santamaria cuckoo in the Liberal nest: old-fashioned, rather rigid, obsessed with sex, a big government man. There was an attractive side to this: he despised racism, didn’t worship the market, didn’t view unions as enemies of the state and wasn’t in politics simply to make Australia more prosperous.

Peter Costello wrote: “He used to tell me proudly that he had learned all of his economics at the feet of Bob Santamaria. I was horrified.”

Right from the start, building a credible political persona was a problem for Abbott. The bits and pieces didn’t fit together. He talked convictions, faith and principles. But what the public saw was an attack dog of remarkable determination, a favoured protégé of John Howard and a young man capable of making the most heartless faux pas.

While values are a plus for an Australian politician, Abbott knew he had to go easy on many of his. As minister for health he deplored the number of abortions in Australia and the storm that caused has never been forgotten. Some have seen him ever since as a Catholic warrior just waiting to pounce.

Barely acknowledged is the fact that he’s done nothing to impose Vatican rules on Australia. True, he doesn’t back gay marriage. Nor did Julia Gillard. But instead of earning credit for his refusal to play the part of Captain Catholic, Abbott arouses suspicion. What had he abandoned? What was merely hidden on the road to power? What lay waiting behind the mask?

The great chameleons of politics are populists. But the magical transformations of Tony Abbott are more driven by tactics than passion: by the need, at any particular moment, to secure advantage. So he reneged on his old support for an emissions trading scheme, won the leadership of the opposition by a single vote and expected this betrayal of his old beliefs to be forgiven by the electorate.

That afternoon he told a rather shell-shocked press conference: “The Australian public are very fair and are always prepared to give a leader of a major political party a fair go … I believe that when you become leader, you make a fresh start.”

Australians don’t see it that way. As his remarkable demolition of Kevin Rudd and the Gillard government proceeded, the polls showed all the old suspicions, the lack of trust, still hovered around Abbott. He was a familiar stranger. The battle didn’t show us much about the man except his skilled ferocity. He came to power not much loved and to a remarkable extent unknown.

New prime ministers need time to reveal themselves. John Howard had Port Arthur to show Australia who he was: a man of greater courage and good sense than his detractors had realised. Abbott has had a difficult slog to a budget that marks yet another transformation of the man.

Abbott 2014 breaks promises. He talks “small government” like the most Reaganite in his party. Out of the blue he wants to reverse the drift of power away from the states he once applauded. He has lost the caution, the instinct for fairness that made him warn against WorkChoices. This budget is WorkChoices for the young and the poor.

It is a hard sell. Abbott does fear well but persuasion is not necessarily his strong suit. It would be so much simpler for him if he were trusted more, if there was a stronger sense out there of who this man is, of how all the pieces of the Abbott puzzle fit together.

If we don’t know by the time the brawls over this budget are done, we will never know. Has a new prime minister in the past half-century faced such challenges: furious state premiers, a hostile senate, a nervous party room, demonstrations, talkback ambush and a profoundly sceptical electorate?

Meanwhile, the budget has solved one old puzzle about Tony: the cuckoo seems finally to have joined the Liberal Party.