Let's start with the iconic leaders of the two major parties: Gough Whitlam and Sir Robert Menzies. Each of these two dominated their respective eras (and the memories of their respective parties in the decades since their time) like Shakespeare's proverbial colossus. They would need to be played as serious Shakespearean roles, by serious Shakespearean actors. Let's say the late Sir John Gielgud as Ming, and the late Sir Laurence Olivier as Gough.
Looking at Whitlam's successor, Malcolm Fraser, this would involve an interesting casting dilemma.
- The Fraser of the Whitlam dismissal would be a menacing character on the scale of Star Wars' Darth Vader.
- On the other hand, the Fraser who first admitted the Vietnamese boat people, and who served as a voice of conscience for the nation on refugee-related issues (and other humanitarian issues) ever since he left active party politics would have been a character such as Gregory Peck's Atticus Finch in To Kill a Mockingbird.
With Bob Hawke, we move from drama to comedy; in particular, to British comedy of the Carry On tradition. Bob Hawke (not only during his political career, but beforehand and afterwards) could most ideally have been portrayed by the late Sid James in any of his Carry On roles, a wheeler-dealer with the proverbial heart of gold, but with a definite eye for the ladies (not to mention an eye on his creature comforts).
Bob Hawke's successor (and party rival) Paul Keating seems to be a character from a "Spaghetti Western", the tall, thin stranger who rides into town with everyone remaining uncertain (frequently until well after the closing credits have rolled and the movie is being dissected over coffee) whether the character was a "good guy" (intentional or unintentional) or a "bad guy" (also intentional or unintentional).
John Howard, because his political career was defined by his relationship vis a vis George W. Bush in the aftermath of 9/11, needs to be in a "sidekick" role.
- One of the great movie sidekicks was the Lone Ranger's friend Tonto, but I think John Howard (given his policies on immigration and related issues while in office) would object to being cast in such a non-Anglo role as Tonto.
- Given the fact that Howard frequently spoke with nostalgia of life in earlier times in history, let's say John Howard could be cast in the role of that other classic sidekick, Barney Rubble from The Flintstones.
For the feuding ALP Prime Ministers who served for the two terms between John Howard and Tony Abbott, we get into the area of TV comedies.
- For Kevin Rudd, I'm thinking of John Cleese's Basil Fawlty from Fawlty Towers (very well-intentioned, but sometimes lacking sufficient people skills to accomplish his desired goals).
- For Julia Gillard, I'm thinking of any of the characters in Seinfeld (equally well-intentioned, but with a tendency to agree to requests which backfire spectacularly).
With Tony Abbott, we have a choice between a return to the Carry On films or a visit to the James Bond series of films.
- On the one hand, Tony Abbott could be seen as any of the characters played by the late Kenneth Williams in the Carry On series.
- On the other hand, Abbott could be a very convincing Bond villain. (However, there were many convincing potential Bond villians in Abbott's cabinet, many of whom were even scarier than Abbott.)
And then, having revised this post to reflect Tony Abbott's departure, finding an actor to play his successor, Malcolm Turnbull, is as easy as casting Gielgud and Olivier as Whitlam and Menzies. Hugh Grant is the obvious choice: suave, articulate, well-meaning in a bumbling sort of way (or should that be "bumbling in a well-meaning sort of way"), wanting to be one of history's "good guys" but prevented by circumstances from allowing his inner Atticus Finch from having too much of an outing. The Hugh Grant of Love Actually is an ideal choice for the lead in Turnbull: the Musical.