ACT Opposition Leader Zed Seselja. Photo: Katherine Griffiths
An ambush on the political incumbent - who would have guessed?
The internecine row now splitting the ACT Liberal Party is the classic scenario of a younger candidate aspiring for the plum post held by an elder statesman.
It has the usual quotient of dirty tricks and bitterness. And none of this comes as a surprise.
The campaign is based on the not-so-subtle theme of generational change - that renewal is always better than the status quo. Again, no surprises there. It's all going according to an established tradition and script.
But it could all come unstuck for Zed Seselja as the backlash grows among Liberal Party members who claim to be disenfranchised. But, if they had so little interest in the party that they haven't been motivated to attend a branch meeting for six months, why would anyone listen to their complaints?
Behind this challenge, Team Zed is suggesting he had the numbers stitched up before he announced his last-minute challenge.
On what grounds can Gary Humphries complain about a challenge? He doesn't, it's the process that irks him.
He's had a decade to cement his position. ''I'm aware that I've had a very great privilege for a number of elections of not facing a challenge.''
If he loses the preselection, it could be because the party wants change. Or is it simply that it is Seselja who wants the change and he has been able to bring the grassroots members with him?
After the ACT election, where he missed the prize by a whisker, Seselja said he had ''no plans'' to enter Federal Parliament. We've all seen that wording before. The ''pledge'' was so generalised you could drive a truck through it with ease.
The irony for Humphries now is the threat against Canberra from his leader. He can make his mark - if he survives.
Now Canberra is hearing Humphries roar like never before, pitching himself as the national capital's champion, indeed the experienced one they're going to need when a Tony Abbott-led government slams Canberra into recession.
This prospect comes just as Humphries is looking for a quest to save his career. To do that, he has to fight Abbott - to stay in the Abbott team.
He could expect to be a frontbench member of an Abbott government, so we need him inside the tent to do our fighting, right?
It was significant that Humphries fired up and used blunt language when he spoke to journalists outside his Civic electorate office.
"There's a particular challenge facing the people of Canberra in the next three years, particularly if there is a change of government. Canberra's going to be facing very heavy pressures. We know that this city will be the subject of some very tough decisions by an incoming government.''
Later: ''Senator, from what you were saying earlier on in your opening statements, are you suggesting that a Tony Abbott government is really going to slam Canberra?''
Humphries: ''I don't think it's any secret … that we're going to reduce the size of the public service. It's very clear that there are going to be some decisions made in that process which will be difficult for Canberra.''
Locals say Humphries backed Seselja to make his original entry into the Assembly. But why should that patronage then hinder Seselja's ambitions now? Politics can be brutal and unforgiving.
Love him or loathe him, Christopher Pyne had to endure an outpouring of opprobrium when he similarly challenged the establishment in Adelaide. Then, as now, he had immense energy and an insatiable appetite for self-promotion, traits that helped him in a 14-month pre-selection battle against Ian Wilson, whose family had held the seat of Sturt for most of the previous 40 years.
Pyne was only 24 at the time of his campaign, which was surrounded by allegations of branch stacking and betrayal. Later he became the numbers man for Peter Costello - who spectacularly failed to challenge John Howard.
Later, Pyne became the parliamentary tactician for the conservative Tony Abbott. Now, the person regarded by many as the most annoying in Australia is within striking distance of becoming a cabinet minister.
In the current Canberra-based power struggle, Humphries must try to put on a good face and paint the challenge as being a welcome exercise in grassroots democracy.
When Seselja became leader, he announced his arrival with television ads that featured a Zorro-like swish of a pen across televisions screens to create a "Z". A striking image.
He didn't stand much of a chance against the hugely popular incumbent but his big achievement was unifying a rabble. Before he took over, the Canberra Liberal MLAs were going through what many political parties do in opposition.
Expectations of success against the government are too high and the growing discontent of frustrated backbenchers results in a "revolving door" of leaders. Just ask federal Labor about its pain during John Howard's long reign.
In Seselja's case, his decision to move to a different electorate to Katy Gallagher allowed him to dominate the southside.
As soon as he lost the electoral prize by the slimmest of margins, speculation began that he would not sit still for another four-year term, but instead switch to federal politics.
That had worked for Humphries. Shortly after losing the post of ACT chief minister, he was allowed to enter the Senate on a casual vacancy created by the resignation of long-serving Liberal, Margaret Reid.
Howard drove Canberra into recession in his first term by cutting tens of thousands of public service jobs. All that changed after 9/11. ASIO and the Australian Federal Police had their numbers massively boosted, and they needed new buildings. Canberra prospered. Not much for a Liberal senator from the ACT to complain about.
More recently Humphries has been vocal about Labor's love of the ''efficiency dividend'' but what can he say about Abbott's plan to cut 12,000 jobs from the public service? Well, the cut will be done by natural attrition and 60 per cent of federal public servants are outside Canberra.
There is a wide expectation that Abbott will ''do a Howard'', that is, blame dire economic circumstances to triple the target of redundancies and also, maybe, make them involuntary.
Watching this unedifying brawl in the Liberal Party is Simon Sheikh, the former GetUp frontman who is standing for the Greens in the ACT.
Younger people arriving in Canberra to work in the public service are changing the way the city votes. In the ACT Senate race, the Greens' first preference vote has gone from 16 per cent in 2004 to almost 23 per cent in 2010.
The minor party can't win when the Liberal Party's natural vote does not fall below 33 per cent, the quota to win. But the Greens believe the brawl in the Liberals will drive votes their way. Sheikh is unlikely to win but he is a young bloke with a national profile and, probably, a five-year plan to enter politics.
Along with the candidate from Katter's Australia Party, he will face either the reinvigorated ''champion'' of Canberra or a younger, ambitious contender looking for a new job.