As talk of a July double dissolution grows louder with every passing week, the government has reached the stage where reverting to a later option will look dangerously like a loss of nerve.
Appalled though some Liberals may be at the prospect of a campaign dragging through most of May and all of June, Prime Minister Malcolm Turnbull would do well to be mindful of what happened in Britain in 2007.
After taking the reins from Tony Blair, Gordon Brown encouraged speculation that he would seek his own mandate through a snap election, only to baulk in the face of a slight dip in the polls -- which was followed by a collapse in public support from which Brown and his government never recovered.
Certainly Turnbull would have a very hard time explaining why he might come to favour a later election that would leave in place the micro-party senators elected in 2013, given his recent rhetoric about the failures of the soon-to-be-reformed Senate electoral system.
This raises the question of what the Senate might look like after a double dissolution, and how voters will behave under the unfamiliar new system.
The uncomfortable fact of the matter is that no one knows for sure, and that many of the assumptions that are informing self-interested calculations on Senate reform could well prove to be misconceived.
Nonetheless, past experience at federal, state and territory level does offer some very strong clues.
There seems little doubt that the overwhelming majority of voters will number six boxes above the line, and no more; that few will deliberately avail themselves of a savings provision that allows for votes to remain in the count where fewer than six boxes are numbered, in defiance of the ballot paper instructions; and that below-the-line voting will remain an indulgence of political junkies, whose exercise of it will have little chance of changing results.
Parties' efforts to corral preferences through how-to-vote cards will have a 40%-50% success rate in the case of the major parties and the Greens, who have the required base of volunteers to distribute the material at polling booths.
However, the preference flows of micro-parties, which have been momentous in their rigidity under the group voting ticket system, are about to become a great deal more scattered.
That being so, what chance is there that lucky micro-party candidates can harness enough preferences to get elected under the new system, as they were increasingly doing under the old?
At a normal half-Senate election, the answer is probably "not all that much". But with 12 seats up for grabs in each state at a double dissolution, and the quota for election down from the usual 14.3% to 7.7%, it's far from clear that the new Senate configuration will be any less complex than the old.
Despite wildly exaggerated talk of a potential Senate majority, the government's realistic hope will be for a manageable crossbench in which regional populists and religious conservatives can be played off against the hostile Labor-Greens bloc.
They will be a long way towards achieving that end if Nick Xenophon's ticket wins three seats, as it will do if it repeats its feat from 2013 of scoring a quarter of the vote in South Australia.
Beyond that, the government can hope for right-wing representation on the crossbench courtesy of the religious parties, of which the Australian Christians are strongest in New South Wales and Western Australia, while Family First prevails elsewhere.
If the past behaviour of below-the-line preferences is anything to go by, these parties' votes will lock in solidly behind each other, and they will get a further fillip when Democratic Labour Party preferences are distributed. That leaves scope for a Coalition surplus to push one of them to victory, provided all the stars align.
Generally speaking, micro-party politics skews to the right, since left-of-centre voters who oppose the two-party system are typically happy to opt for the Greens. However, life for the government could yet be made more complicated by a growing market for parties distinguished by their hostility to social conservatism, who are nonetheless uncomfortable with the Greens' big-government instincts.
Perhaps the most underrated prospect is the Australian Sex Party, whose failure to win Senate seats under the old system seems to have encouraged a presumption that it won't do so under the new one either.
However, the party did manage to win one seat, and very nearly two, under the unreformed system for Victoria's state upper house in 2014, and there is reason to expect that consciously directed preferences will play in its favour in the context of a double dissolution.
At the 2013 federal election, the Sex Party was the strongest performer out of what might be identified as a "left-libertarian" bloc encompassing the Pirate Party, which represents an internet-age brand of social liberalism that has yielded electoral successes for sibling parties in Germany and Sweden; the long-established and self-explanatory Help End Marijuana Prohibition; and the now defunct WikiLeaks Party (it should be noted that these voters did not favour the Liberal Democratic Party, which seems to be struggling to convey the message that it is libertarian rather than conservative).
Below-the-line preference trends suggest a good two-thirds of these votes should find their way to the Sex Party, given a half-way manageable ballot paper.
Furthermore, the party's name appears to catch the eye of many supporters of weakly ideological parties from the Palmer United Party to the various shooting, fishing and outdoor recreation concerns, with only religious conservatives conspicuously shying away.
In the particularly promising case of Victoria, the 2013 election result suggests this could all add up to nearly 5% of the vote -- well on the way to a quota, particularly if there is a substantial surplus after the last Labor and Greens Senators are elected.
Ultimately, the result of a double dissolution seems likely to deliver the electorate what it ordered -- an eclectic mix between the Coalition and Labor-Greens blocs that recognises real tendencies within the electorate, in contrast to the perverse and arbitrary combinations thrown up by the old system.
The real test of the system's capacity to represent anti-establishment sentiment will come later, when consecutive normal elections produce a chamber elected entirely under the formidable quota that applies at half-Senate elections.